Science.gov

Sample records for alkyl substituted phenols

  1. 40 CFR 721.3812 - Substituted phenols and formaldehyde polymer, alkylated (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polymer, alkylated (generic). 721.3812 Section 721.3812 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3812 Substituted phenols and formaldehyde polymer... substance identified generically as substituted phenols and formaldehyde polymer, alkylated (PMN...

  2. 40 CFR 721.3812 - Substituted phenols and formaldehyde polymer, alkylated (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polymer, alkylated (generic). 721.3812 Section 721.3812 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3812 Substituted phenols and formaldehyde polymer... substance identified generically as substituted phenols and formaldehyde polymer, alkylated (PMN...

  3. 40 CFR 721.3812 - Substituted phenols and formaldehyde polymer, alkylated (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polymer, alkylated (generic). 721.3812 Section 721.3812 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3812 Substituted phenols and formaldehyde polymer... substance identified generically as substituted phenols and formaldehyde polymer, alkylated (PMN...

  4. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  5. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  6. 40 CFR 721.3812 - Substituted phenols and formaldehyde polymer, alkylated (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polymer, alkylated (generic). 721.3812 Section 721.3812 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3812 Substituted phenols and formaldehyde polymer... substance identified generically as substituted phenols and formaldehyde polymer, alkylated (PMN...

  7. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  8. 40 CFR 721.3812 - Substituted phenols and formaldehyde polymer, alkylated (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polymer, alkylated (generic). 721.3812 Section 721.3812 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3812 Substituted phenols and formaldehyde polymer... substance identified generically as substituted phenols and formaldehyde polymer, alkylated (PMN...

  9. 40 CFR 721.10038 - Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Trimellitic anhydride, polymer with... Trimellitic anhydride, polymer with substituted glycol, alkyl phenols and ethoxylated nonylphenol (generic... identified generically as trimellitic anhydride, polymer with substituted glycol, alkyl phenols...

  10. Binding of alkyl- and alkoxy-substituted simple phenolic compounds to human serum proteins.

    PubMed

    Ogata, N; Shibata, T

    2000-01-01

    Wood creosote, primarily a mixture of simple alkyl- and/or alkoxy-substituted phenolic compounds with closely related structures, has long been used as an oral antidiarrheal agent. The use of wood creosote as a parenteral antidiarrheal agent was investigated, and for basic pharmacokinetic data we measured the extent of equilibrium binding of its six major constituent phenolic compounds to human serum proteins using an ultrafiltration method. The percent binding of these major constituent phenolic compounds, namely phenol, guaiacol, p-cresol, o-cresol, creosol and 4-ethylguaiacol, bound to 40-mg/ml human serum albumin was 15.5+/-0.9, 28.0+/-1.5, 37.2+/-0.7, 52.3+/-5.3, 36.8+/-2.0 and 56.7+/-2.4%, respectively, while percent binding to human serum (68 mg protein/ml) was 41.3+/-0.7, 42.6+/-0.5, 64.8+/-0.4, 70.1+/-1.6, 65.7+/-0.2 and 83.1+/-0.1% (mean +/- standard deviation, n = 4), respectively, when tested individually at a concentration of 500 micromol/l. Saturation of binding was not observed for the phenolic compounds up to a concentration of 50 mmol/l. Phenolic compounds with a lipophilic substituent showed higher percent binding to proteins than those without it. We conclude that simple phenolic compounds having alkyl- and/or alkoxy-substituents bind to serum proteins to a considerable extent and that the binding is hydrophobic and nonspecific.

  11. Enantioselective synthesis of 4-substituted tetrahydroisoquinolines via palladium-catalyzed intramolecular Friedel-Crafts type allylic alkylation of phenols.

    PubMed

    Zhao, Zheng-Le; Xu, Qing-Long; Gu, Qing; Wu, Xin-Yan; You, Shu-Li

    2015-03-14

    Palladium-catalyzed asymmetric intramolecular Friedel-Crafts type allylic alkylation reaction of phenols was developed under mild conditions. In the presence of Pd2(dba)3 with (1R,2R)-DACH-phenyl Trost ligand (L2) in toluene at 50 °C, the reaction provides various C4 substituted tetrahydroisoquinolines with moderate to excellent yields, regioselectivity and enantioselectivity.

  12. Demonstration of two functionally heterogenous groups within the activities of UDP-glucuronosyltransferase towards a series of 4-alkyl-substituted phenols.

    PubMed Central

    Wishart, G J; Campbell, M T

    1979-01-01

    1. A simple colorimetric assay for UDP-glucuronosyltransferase activities towards phenolic substrates, using Folin & Ciocalteu's phenol reagent, is described. The assay is used to measure rat liver transferase activities towards substrates from a series of 4-alkyl-substituted phenols. 2. Activities towards phenol, 4-methylphenol and 4-ethylphenol develop near-adult values before birth, are precociously stimulated by dexa methasone in utero and are stimulated 3--4-fold by 3-methylcholanthrene in adult liver. These are assigned to a "late-foetal" group of transferase activities. 3. Activities towards 4-n-propylphenol, 4-s-butylphenol and 4-t-butylphenol are negligible in late-foetal liver, developing to near-adult values in the first 4 postnatal days, and are not affected by dexamethasone or 3-methylcholanthrene. They are assigned to a "neonatal" group of transferase activities. 4. Although 4-ethylphenol and 4-n-propylphenol differ only by a single --CH2-- moiety, this is sufficient to change the acceptability of these substrates respectively from the late-foetal to the neonatal group of transferase activities. The change is distinct, with no overlapping of substrate acceptability between the two groups of transferase activities. 5. From consideration of the above and other substrates, the two groups of transferase activities do not distinguish substrates on the basis of their molecular weights or lipophilicity. The distinguishing feature appears to be the specific molecular configurations of the substrates. PMID:109087

  13. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  14. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  15. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  16. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  17. 40 CFR 721.5769 - Mixture of nitrated alkylated phenols.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixture of nitrated alkylated phenols... Substances § 721.5769 Mixture of nitrated alkylated phenols. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a mixture of nitrated alkylated...

  18. 40 CFR 721.5867 - Substituted phenol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phenol. 721.5867 Section... Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted phenol (PMNs P-89-1125,...

  19. Soluble Alkyl Substituted Polygermanes. Thermochromic Behavior.

    DTIC Science & Technology

    1986-07-17

    are strongly thermochromic . The effect is attributed to conformational locking of the backbone which is caused by the crystallization of the side groups...are strongly thermochromic . The effect is attributed to the conformational locking of the backbone which is caused by the crystallization of the side...SYMBOL. 02 &m A -- .- h.. .. .. . . . . . . . . ... . . . .. RJ 5008 (52258) 1/24/86 Chemis try SOLUBLE ALKYL SUBSTITUTED POLYGERMANES: THERMOCHROMIC

  20. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl amino substituted triazine...

  1. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl amino substituted triazine...

  2. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl amino substituted triazine...

  3. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl amino substituted triazine...

  4. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl amino substituted triazine...

  5. 40 CFR 721.10711 - Alkyl substituted catechol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl substituted catechol (generic... Specific Chemical Substances § 721.10711 Alkyl substituted catechol (generic). (a) Chemical substance and... substituted catechol (PMN P-13-197) is subject to reporting under this section for the significant new...

  6. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  7. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  8. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  9. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  10. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  11. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  12. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  13. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  14. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  15. 40 CFR 721.840 - Alkyl substituted diaromatic hydrocarbons.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrocarbons. 721.840 Section 721.840 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.840 Alkyl substituted diaromatic hydrocarbons. (a) Chemical substance... alkyl substituted di-aro-matic hydrocarbons (PMN P-91-710) is subject to reporting under this...

  16. Selective catalytic hydroalkylation and deoxygenation of substituted phenols to bicycloalkanes

    SciTech Connect

    Zhao, Chen; Camaioni, Donald M.; Lercher, Johannes A.

    2012-04-01

    Phenol and substituted phenols are hydroalkylated and hydrodeoxygenated to bi-cycloalkanes in a tandem reaction over Pd nanoclusters supported on a large-pore molecular sieve HBEA at 473-523 K using water as solvent. The HBEA-supported Pd catalyst (metal-acid ratio: 1:22 mol/mol) optimally balances the competing rates of metal catalyzed hydrogenation as well as of solid acid-catalyzed dehydration and carbon-carbon coupling to combine hydrodeoxygenation and dimerization of phenol derivatives to C{sub 12}-C{sub 18} bicycloalkanes in a single reaction sequence. A detailed kinetic study of the elementary reactions of (substituted) phenol and their potential products (cyclohexanol, cyclohexanone, and cyclohexene) demonstrates that phenol selectively reacts with the in situ generated cyclohexanol or cyclohexene on Broensted acid sites. The acid-catalyzed alkylation of phenol with alcohol intermediates and alcohol dehydration are parallel reactions, which are subtly influenced by the competing hydrogenation reactions as well as by the presence of water as solvent. IR spectroscopy of adsorbed species and preliminary molecular modeling indicate that phenol and cyclohexanol enrichment in the large pores of zeolite HBEA is critical for the high activity and hydroalkylation selectivity.

  17. 40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted alkyl ester, hydrolysis... ester, hydrolysis products with silica and substituted silane (generic). (a) Chemical substance and... alkyl ester, hydrolysis products with silica and substituted silane (PMNs P-06-276 and P-06-279)...

  18. 40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted alkyl ester, hydrolysis... ester, hydrolysis products with silica and substituted silane (generic). (a) Chemical substance and... alkyl ester, hydrolysis products with silica and substituted silane (PMNs P-06-276 and P-06-279)...

  19. Acute aquatic toxicity of alkyl phenol ethoxylates

    SciTech Connect

    Schueuermann G2 )

    1991-04-01

    The recently derived log Kow (octanol/water partition coefficient in logarithmic form) increment for a nonterminal oxyethylene unit was used to calculate a quantitative structure-activity relationships for literature data on the acute crustacean toxicity of polyoxyethylene surfactants. The resulting log Kow regression parameters are between the corresponding values for nonpolar and polar narcosis, which supports an interpretation of the surfactants' aquatic toxicity on the basis of another distinct mode of action. Furthermore, a comparison with calculated water solubility data indicates that for log Kow greater than 5 an aquatic toxicity decrease due to a solubility limit is expected, which gets support from two other sets on toxicity data of nonyl phenol polyethoxylates.

  20. Effects of alkyl substitutions of xanthine skeleton on bronchodilation.

    PubMed

    Sakai, R; Konno, K; Yamamoto, Y; Sanae, F; Takagi, K; Hasegawa, T; Iwasaki, N; Kakiuchi, M; Kato, H; Miyamoto, K

    1992-10-30

    Structure-activity relationships in a series of 1,3,7-trialkyl-xanthine were studied with guinea pigs. Relaxant actions in the tracheal muscle were increased with alkyl chain length at the 1- and 3-positions of the xanthine skeleton, but decreased by alkylation at the 7-position. Positive chronotropic actions in the right atrium were potentiated with 3-alkyl chain length but tended to decrease with 1-alkylation and diminish by 7-substitution. Consequently, while the 1- and 3-substitutions were equally important for the tracheal smooth muscle relaxation, the substitution at the 1-position was more important than the 3-substitution for bronchoselectivity. The 7-alkylation may be significant to cancel heart stimulation. There were good correlations between the smooth muscle relaxant action and the cyclic AMP-PDE inhibitory activity in 3-substituents and the affinity for adenosine (A1) receptors in 1-, 3-, and 7-substituents. This suggests that not only the cyclic AMP-PDE inhibitory activity but also the adenosine antagonistic activity is important in the bronchodilatory effects of alkylxanthines. Among these xanthine derivatives, 1-butyl-3-propylxanthine and its 7-methylated derivative showed high bronchoselectivity in the in vitro and in vivo experiments compared to theophylline and enprofylline and may be new candidates for bronchodilator.

  1. 40 CFR 721.843 - Substituted phenylazophenylazo phenol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted phenylazophenylazo phenol... Specific Chemical Substances § 721.843 Substituted phenylazophenylazo phenol (generic). (a) Chemical... as substituted phenylazophenylazo, phenol (PMN P-00-0420) is subject to reporting under this...

  2. 40 CFR 721.7210 - Epoxidized copolymer of phenol and substituted phenol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxidized copolymer of phenol and substituted phenol. 721.7210 Section 721.7210 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7210 Epoxidized copolymer of phenol and substituted phenol. (a)...

  3. Laser processing of phenolic wood substitutes

    NASA Astrophysics Data System (ADS)

    Quintero, F.; Riveiro, A.; Lusquiños, F.; Penide, J.; Arias-González, F.; del Val, J.; Comesaña, R.; Boutinguiza, M.; Pou, J.

    2013-11-01

    Phenolic resin boards (PRB) are wood substitutes that comprises of a thick core exclusively made of phenolic resin covered by a thin sheet of melamine resin imitating the aspect of natural wood. The use of these materials in furniture and in construction industry has proliferated during last years. Boards made of phenolic resins are dense, hard and very difficult to cut using band saws, disc saws, or milling cutters. Nevertheless, these difficulties can be overcome by means of laser cutting, which is one of the most firmly established techniques for separating materials. This is due to the great advantages of this technique over traditional cutting methods, such as its versatility and flexibility that allow effective cutting. Nevertheless, charring of the cut edge surface caused by laser induced thermal degradation degrades the cut quality under non-optimized processing conditions. In this research work the viability and quality of CO2 laser cutting process of phenolic resin boards and wood particleboard panels has been evaluated. The present work validates the cut of phenolic resin boards by CO2 lasers using a high laser power and elevated cutting speeds. Moreover, this process involves a serious health hazard since the combustion and decomposition of wood may produce fumes and vapors, which can be toxic and carcinogenic according to the International Chemical Safety Cards (ICSC). Therefore, this work was complemented by the assessment of the potential toxicity of the condensed residues formed on the cut edges, and assessment of the chemistry of the generated fumes by chromatography.

  4. 40 CFR 721.10498 - Substituted alkyl ester, hydrolysis products with silica (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted alkyl ester, hydrolysis... Significant New Uses for Specific Chemical Substances § 721.10498 Substituted alkyl ester, hydrolysis products... chemical substances identified generically as substituted alkyl ester, hydrolysis products with...

  5. 40 CFR 721.10498 - Substituted alkyl ester, hydrolysis products with silica (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted alkyl ester, hydrolysis... Significant New Uses for Specific Chemical Substances § 721.10498 Substituted alkyl ester, hydrolysis products... chemical substances identified generically as substituted alkyl ester, hydrolysis products with...

  6. 40 CFR 721.10517 - Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (generic). 721.10517... Substances § 721.10517 Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (PMN P-10-485) is...

  7. 40 CFR 721.10517 - Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (generic). 721.10517... Substances § 721.10517 Alkyl methacrylates, polymer with substituted carbomonocycle, hydroxymethyl acrylamide... substituted carbomonocycle, hydroxymethyl acrylamide and fluorinatedalkyl acrylate (PMN P-10-485) is...

  8. Alkylation of terminal alkynes with transient σ-alkylpalladium(II) complexes: a carboalkynylation route to alkyl-substituted alkynes.

    PubMed

    Zhou, Ming-Bo; Huang, Xiao-Cheng; Liu, Yan-Yun; Song, Ren-Jie; Li, Jin-Heng

    2014-02-10

    A mild and general alkylation of terminal alkynes with transient σ-alkylpalladium(II) complexes for assembling alkyl-substituted alkynes is described. This method represents a new way to the use of transient σ-alkylpalladium(II) complexes in organic synthesis through 1,2-carboalkynylation of alkenes.

  9. Alkylation of phenol with polybutenes in the presence of benzenesulfonic acid

    SciTech Connect

    Belov, P.S.; Gulyaev, I.A.; Korenev, K.D.; Yakovlev, V.B.; Zakupra, V.A.

    1982-09-01

    The purpose of this work is to test benzenesulfonic acid (BSA) as a catalyst in the alkylation of phenol with polyisobutylene (PIB). This material is used as a catalyst in the production of technical C/sub 5/-C/sub 12/ tert-alkylphenol. Finds that the optimal compromise between acceleration of the reaction and the alkylate viscosity increase that limits the reaction rate is achieved at a temperature of about 105 C and a BSA/PIB mole ratio of 0.15. Recommends BSA as an effective replacement for boron fluoride, boron fluoride complexes, and other highly corrosive catalysts used in the alkylation of phenol with polybutenes.

  10. Pseudo-hydroxide extraction in the separation of sodium hydroxide from aqueous solutions using alkyl phenols

    SciTech Connect

    Kang, Hyun Ah; Moyer, Bruce A

    2006-01-01

    Pseudo-hydroxide extraction of sodium hydroxide from aqueous solution using four alkyl phenols of nearly identical molecular weight in 1-octanol at 25 degrees C was examined to understand the effect of alkyl substituents. The order of extraction strength among the four alkyl phenols tested was 4-tert-octylphenol. 3,5-di-tertbutylphenol. 2,4-di-tert-butylphenol. 2,6-di-tert-butyl-4-methylphenol. A good correlation with phenol pK(a) was observed, indicating that extraction strength is determined by phenol acidity, as modified by steric effects in proximity to the phenol - OH group. The effective partition ratios (P-eff) of two phenols from 1 M NaOH solution were determined, showing that the phenols remain predominantly in the 1-octanol phase even when converted to their sodium salts. However, the hydrophobicity of the tested phenols may not be sufficient for process purposes. The equilibrium constants for the governing extraction equilibria were determined by modeling the data using the program SXLSQI, supporting the cation-exchange extraction mechanism. The proposed mechanism consists of two simple sets of equilibria for a. Ion-pair extraction to give Na+OH- ion pairs and corresponding free ions in 1-octanol the phase and b. Cation exchange by monomeric phenol molecules (HAs) to form monomeric organic-phase Na(+)A(-) ion pairs and corresponding free organic-phase ions.

  11. Thermal decomposition of substituted phenols in supercritical water

    SciTech Connect

    Martino, C.J.; Savage, P.E.

    1997-05-01

    The thermal decomposition of cresols, hydroxybenzaldehydes, nitrophenols, and benzenediols was studied in dilute aqueous solutions and in the absence of oxygen at 460 C and 250 atm for residence times around 10 s. Thermolysis under these conditions produced conversions of less than 10% for o-, m-, and p-cresol, whereas hydroxybenzaldehydes and nitrophenols were much more reactive. Global rate expressions are reported for the thermolysis of each hydroxybenzaldehyde and nitrophenol isomer. Phenol was a major product from the decomposition of all of the substituted phenols studied. For a given substituent, ortho-substituted phenols reacted more rapidly than the other isomers. For a given substituted position, nitrophenols reacted more rapidly than hydroxybenzaldehydes, which in turn reacted more rapidly than cresols. These results demonstrate that the treatment of CHO- and NO{sub 2}-substituted phenols by oxidation in supercritical water will involve the oxidation of thermal decomposition products in addition to the oxidation of the original compounds.

  12. Molecular dynamics simulations of alkyl substituted nanographene crystals

    NASA Astrophysics Data System (ADS)

    Ziogos, Orestis George; Theodorou, Doros Nicolas

    2015-09-01

    Discotic polyaromatic molecules, similar to nanometric graphene flakes, constitute an interesting class of materials for organic electronic applications. Grafting flexible side chains around the periphery of such molecules enhances their processability and gives rise to diverse behaviours, such as the manifestation of liquid-crystalline character and anisotropic mechanical response. In this work, we examine by means of molecular dynamics simulations the properties of molecular crystals comprised of alkyl-substituted hexa-peri-hexabenzocoronene mesogens. Pristine and mono-substituted systems by hydrogen or iodine atoms are modelled, with variable side chain length. A general structural and mechanical robustness to peripheral substitution is reported, with the mesogens forming tightly packed molecular wires even at elevated temperature and pressure. In their discotic ordering, the molecules present relatively low translational mobility, a beneficial phenomenon for charge transport. A thermotropic dependence of the mechanical response is identified, with the systems behaving differently in their room-temperature crystalline phase and in their liquid-crystalline phase at elevated temperatures. The melting process is also examined, elucidating an initial negative expansion along a high symmetry direction and the existence of a metastable state, before falling into the final liquid-crystalline state. Dedicated to Professor Jean-Pierre Hansen, with deepest appreciation of his outstanding contributions to liquid and soft matter theory.

  13. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted oxirane, formaldehyde-phenol polymer glycidyl ether, substituted proplyamine and...-phenol polymer glycidyl ether, substituted proplyamine and polyethylenepolyamines (generic). (a) Chemical... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  14. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted oxirane, formaldehyde-phenol polymer glycidyl ether, substituted proplyamine and...-phenol polymer glycidyl ether, substituted proplyamine and polyethylenepolyamines (generic). (a) Chemical... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  15. Masked N-Heterocyclic Carbene-Catalyzed Alkylation of Phenols with Organic Carbonates.

    PubMed

    Lui, Matthew Y; Yuen, Alexander K L; Masters, Anthony F; Maschmeyer, Thomas

    2016-09-08

    An easily prepared masked N-heterocyclic carbene, 1,3-dimethylimidazolium-2-carboxylate (DMI-CO2 ), was investigated as a "green" and inexpensive organocatalyst for the alkylation of phenols. The process made use of various low-toxicity and renewable alkylating agents, such as dimethyl- and diethyl carbonate, in a focused microwave reactor. DMI-CO2 was found to be a very active catalyst and excellent yields of a range of aryl alkyl ethers were obtained under relatively benign conditions. The observed difference in the conversion behavior of phenol methylation, in the presence of either the carbene or 1,8-diazabicycloundec-7-ene (DBU) catalyst, was rationalized on the basis of mechanistic investigations. The primary mode of action for the N-heterocyclic carbene is nucleophilic catalysis. Activation of the dialkyl carbonate electrophile results in concomitant evolution of an organo-soluble alkoxide, which deprotonates the phenolic starting material. In contrast, DBU is initially protonated by the phenol and thus consumed. Subsequent regeneration and participation in nucleophilic catalysis only becomes significant after some phenolate alkylation occurs.

  16. Heterogeneous catalysis by solid superacids--14. Perfluorinated resinsulfonic acid (nafion-h) catalyzed Friedel-crafts alkylation of toluene and phenol with alkyl chloroformates and oxalates

    SciTech Connect

    Olah, G.A.; Meidar, D.; Malhotra, R.; Olah, J.A.; Narang, S.C.

    1980-01-01

    Product distributions obtained in the alkylation of toluene with methyl, ethyl, and isopropyl chloroformate and dimethyl oxalate and of phenol with methyl and ethyl chloroformate and dimethyl- and diethyloxalate.

  17. REVISITING CLASSICAL NUCLEOPHILIC SUBSTITUTIONS IN AQUEOUS MEDIUM: MICROWAVE-ASSISTED SYNTHESIS OF ALKYL AZIDES

    EPA Science Inventory

    An efficient and clean synthesis of alkyl azides using microwave (MW) radiation is described in aqueous medium by reacting alkyl halides or tosylates with alkali azides. This general and expeditious MW-enhanced approach to nucleophilic substitution reactions is applicable to the ...

  18. Characterization of phenol and alkyl phenols in organic matrixes with monoethylene glycol extraction and multidimensional gas chromatography/mass spectrometry.

    PubMed

    Luong, J; Gras, R; Cortes, H J; Shellie, R A

    2013-07-02

    The use of monoethylene glycol as an extraction medium for removing phenol and alkyl phenols in organic matrixes such as hydrocarbons is introduced and combined with a practical analytical multidimensional gas chromatography approach. The analytical approach has been successfully developed for the characterization of phenol, cresols, xylenols, and alkyl phenols like 4-ethylphenol and 2,3,5-trimethylphenol. The technique employs a single-step extraction of the analytes with monoethylene glycol and sonication, followed by multidimensional gas chromatography with mass spectrometry in selected ion monitoring mode for the detection and quantitation. Extraction efficiency of phenol approached 100% while cresols, xylenols, and 4-ethylphenol were 97% or higher and 2,3,5-trimethylphenol was better than 91% under the analytical conditions used. With the technique described, a complete analysis can be conducted in less than 16 min. Reproducibility of area counts at two levels, namely, 5 ppm(w) and 50 ppm(w) over a period of 2 days were found to be less than 4% (n = 20). The analytes of interest was found to be linear over a range from 100 ppb(w) to 250 ppm(w) with correlation coefficient of at least 0.999 and detection limit of 50 ppb(w) . Spike recoveries from 500 ppb(w) to 250 ppm(w) for all analytes range from 96 to 102%.

  19. Stereochemistry analysis and comparison of two C(3)-alkyl substituted cyclohexonedicarboxylates with their C(3)-aryl substituted analogues

    NASA Astrophysics Data System (ADS)

    Chen, Chao-Yue; Wang, Qi; Zhu, Bing-Long; Zhao, Wen-Jie; Hu, Jin-Song

    2016-03-01

    Two representative C(3)-alkyl substituted cyclohexonedicarboxylates (4a and 4b) were synthesized and their conformational features were investigated by single crystal X-ray crystallography for the first time. These stereochemistry results of 4a and 4b were compared with those obtained from the earlier research of C(3)-aryl substituted analogues (1-3).

  20. Chiral Brønsted Base-Promoted Nitroalkane Alkylation: Enantioselective Synthesis of sec-Alkyl-3-Substituted Indoles

    PubMed Central

    Dobish, Mark C.; Johnston, Jeffrey N.

    2010-01-01

    A Brønsted base-catalyzed reaction of nitroalkanes with alkyl electrophiles provides indole heterocycles substituted at C3 bearing a sec-alkyl group with good enantioselectivity (up to 90% ee). Denitration by hydrogenolysis provides a product with equally high ee. An indolenine intermediate is implicated in the addition step, and surprisingly, water cosolvent was found to have a beneficial effect in this step, leading to a one-pot protocol for elimination/enantioselective addition using PBAM, a bis(amidine) chiral nonracemic base. PMID:21090654

  1. 40 CFR 721.10606 - Alkyl substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl substituted alkanediol polymer... alkanediol polymer with aliphatic and alicyclic diisocyanates (generic). (a) Chemical substance and... substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (PMN P-11-486) is subject...

  2. 40 CFR 721.10606 - Alkyl substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl substituted alkanediol polymer... alkanediol polymer with aliphatic and alicyclic diisocyanates (generic). (a) Chemical substance and... substituted alkanediol polymer with aliphatic and alicyclic diisocyanates (PMN P-11-486) is subject...

  3. Alkylated phenol series in lacustrine black shales from the Nördlinger Ries, southern Germany.

    PubMed

    Barakat, Assem O; Baumgart, Susan; Brocks, Peter; Scholz-Böttcher, Barbara M; Rullkötter, Jürgen

    2012-08-01

    Several series of alkylated phenols were detected for the first time in the extractable bitumens of organic matter-rich sediments from the Nördlinger Ries (southern Germany). Most abundant and significant constituents comprise those with n-octadecyl, n-eicosanyl, phytanyl, and iso-pentadecyl and anteiso-pentadecyl substituents. The structures of these compounds are suggested from mass spectrometric and retention time data and coinjection with synthetic standards. Diagenetic alteration of phenolic algal lipids is suggested as a possible way to the formation of these compounds in the Nördlinger Ries sediments.

  4. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified reaction products of alkyl... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  5. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified reaction products of alkyl... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  6. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified reaction products of alkyl... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  7. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified reaction products of alkyl... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  8. 40 CFR 721.10145 - Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified reaction products of alkyl... Modified reaction products of alkyl alcohol, halogenated alkane, substituted epoxide, and amino compound... identified generically as modified reaction products of alkyl alcohol, halogenated alkane,...

  9. Symmetry matters: photodissociation dynamics of symmetrically versus asymmetrically substituted phenols.

    PubMed

    Karsili, Tolga N V; Wenge, Andreas M; Marchetti, Barbara; Ashfold, Michael N R

    2014-01-14

    We report a combined experimental (H (Rydberg) atom photofragment translational spectroscopy) and theoretical (ab initio electronic structure and vibronic coupling calculations) study of the effects of symmetry on the photodissociation dynamics of phenols. Ultraviolet photoexcitation to the bound S1((1)ππ*) state of many phenols leads to some O-H bond fission by tunneling through the barrier under the conical intersection (CI) between the S1 and dissociative S2((1)πσ*) potential energy surfaces in the R(O-H) stretch coordinate. Careful analysis of the total kinetic energy release spectra of the resulting products shows that the radicals formed following S1 ← S0 excitation of phenol and symmetrically substituted phenols like 4-fluorophenol all carry an odd number of quanta in vibrational mode ν(16a), whereas those deriving from asymmetrically substituted systems like 3-fluorophenol or 4-methoxyphenol do not. This contrasting behavior can be traced back to symmetry. Symmetrically substituted phenols exist in two equivalent rotamers, which interconvert by tunneling through the barrier to OH torsional motion. Their states are thus best considered in the non-rigid G4 molecular symmetry group, wherein radiationless transfer from the S1 to S2 state requires a coupling mode of a2 symmetry. Of the three a2 symmetry parent modes, the out-of-plane ring puckering mode ν(16a) shows much the largest interstate coupling constant in the vicinity of the S1/S2 CI. The nuclear motions associated with ν(16a) are orthogonal to the dissociation coordinate, and are thus retained in the radical products. Introducing asymmetry (even a non-linear substituent in the 4-position) lifts the degeneracy of the rotamers, and lowers the molecular symmetry to Cs. Many more parent motions satisfy the reduced (a'') symmetry requirement to enable S1/S2 coupling, the most effective of which is OH torsion. This motion 'disappears' on O-H bond fission; symmetry thus imposes no restriction to

  10. Microbial Degradation and Assimilation of n-Alkyl-Substituted Cycloparaffins1

    PubMed Central

    Beam, H. W.; Perry, J. J.

    1974-01-01

    Studies were conducted on the oxidation and assimilation of n-alkyl-substituted cycloalkane substrates by several hydrocarbon-utilizing microorganisms. These microorganisms utilized heptadecylcyclohexane and dodecylcyclohexane as the sole source of carbon and energy. Neither methylcyclohexane nor ethylcyclohexane was utilized as a growth substrate by any organisms tested. Gas-liquid chromatographic analyses of fatty acids present in cells after growth on dodecylcyclohexane confirm direct incorporation of both alpha- and beta-oxidation products. Growth patterns of these organisms on n-alkyl-substituted cyclohexane fatty acids of varying chain lengths suggest a greater probability of ring cleavage when the side chain contains an odd number of carbons. PMID:4597441

  11. Redox Potentials, Laccase Oxidation, and Antilarval Activities of Substituted Phenols

    PubMed Central

    Prasain, Keshar; Nguyen, Thi D. T.; Gorman, Maureen J.; Barrigan, Lydia M.; Peng, Zeyu; Kanost, Michael R.; Syed, Lateef U.; Li, Jun; Zhu, Kun Yan; Hua, Duy H.

    2012-01-01

    Laccases are copper-containing oxidases that are involved in sclerotization of the cuticle of mosquitoes and other insects. Oxidation of exogenous compounds by insect laccases may have the potential to produce reactive species toxic to insects. We investigated two classes of substituted phenolic compounds, halogenated di- and trihydroxybenzenes and substituted di-tert-butylphenols, on redox potential, oxidation by laccase and effects on mosquito larval growth. An inverse correlation between the oxidation potentials and laccase activity of halogenated hydroxybenzenes was found. Substituted di-tert-butylphenols however were found to impact mosquito larval growth and survival. In particular, 2,4-di-tert-butyl-6-(3-methyl-2-butenyl)phenol (15) caused greater than 98% mortality of Anopheles gambiae larvae in a concentration of 180 nM, whereas 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-methylpropanal oxime (13) and 6,8-di-tert-butyl-2,2-dimethyl-3,4-dihydro-2H-chromene (33) caused 93% and 92% mortalities in concentrations of 3.4 and 3.7 μM, respectively. Larvae treated with di-tert-butylphenolic compounds died just before pupation. PMID:22300888

  12. Enantioselective Friedel-Crafts Alkylation Reactions of 3-Substituted Indoles with Electron-Deficient Alkenes.

    PubMed

    Weng, Jian-Quan; Fan, Ren-Jie; Deng, Qiao-Man; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-04-01

    Highly enantioselective Friedel-Crafts C2-alkylation reactions of 3-substituted indoles with α,β-unsaturated esters and nitroalkenes were developed using chiral Lewis acids as catalysts, which afforded chiral indole derivatives bearing C2-benzylic stereogenic centers in good to excellent yields (up to 99%) and enantioselectivities (up to 96% ee).

  13. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  14. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  15. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  16. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  17. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  18. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  19. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  20. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  1. 40 CFR 721.7220 - Polymer of substituted phenol, formaldehyde, epichlorohydrin, and disubstituted benzene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of substituted phenol... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7220 Polymer of substituted phenol... subject to reporting. (1) The chemical substance identified generically as polymer of substituted...

  2. 40 CFR 721.7046 - Formaldehyde, polymer with substituted phenols, glycidyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymer with substituted... New Uses for Specific Chemical Substances § 721.7046 Formaldehyde, polymer with substituted phenols... substance identified as formaldehyde, polymer with substituted phenols, glycidyl ether (PMN P-93-955)...

  3. Characterization of alkyl phenols in cashew (Anacardium occidentale) products and assay of their antioxidant capacity.

    PubMed

    Trevisan, M T S; Pfundstein, B; Haubner, R; Würtele, G; Spiegelhalder, B; Bartsch, H; Owen, R W

    2006-02-01

    In this study the content of anacardic acids, cardanols and cardols in cashew apple, nut (raw and roasted) and cashew nut shell liquid (CNSL) were analysed. The higher amounts (353.6 g/kg) of the major alkyl phenols, anacardic acids were detected in CNSL followed by cashew fibre 6.1 g/kg) while the lowest (0.65 g/kg) amounts were detected in roasted cashew nut. Cashew apple and fibre contained anacardic acids exclusively, whereas CNSL also contained an abundance of cardanols and cardols. Cashew nut (raw and roasted) also contained low amounts of hydroxy alkyl phenols. Cashew nut shell liquid was used for a basic fractionation of the alkyl phenol classes and the individual anacardic acids, major cardanols and cardols were purified to homogeneity from these fractions by semi-preparative HPLC and definitively identified by nano-ESI-MS-MS, GC-MS and NMR analyses. The hexane extracts (10 mg/ml) of all cashew products tested plus CNSL, displayed significant antioxidant capacity. Cashew nut shell liquid was the more efficient (inhibition=100%) followed by the hexane extract of cashew fibre (94%) and apple (53%). The antioxidant capacity correlated significantly (P<0.05) with the concentration of alkyl phenols in the extracts. A mixture of anacardic acids (10.0 mg/ml) showed the higher antioxidant capacity (IC50=0.60 mM) compared to cardols and cardanols (IC50>4.0 mM). The data shows that of these substances, anacardic-1 was by far the more potent antioxidant (IC50=0.27 mM) compared to cardol-1 (IC50=1.71 mM) and cardanol-1 (IC50>4.0 mM). The antioxidant capacity of anacardic acid-1 is more related to inhibition of superoxide generation (IC50=0.04 mM) and xanthine oxidase (IC50=0.30 mM) than to scavenging of hydroxyl radicals. At present a substantial amount of cashew fibre is mostly used in formulations of animal or poultry feeds. The data presented in this study, indicates that this waste product along with CNSL, both of which contain high contents of anacardic acids

  4. Retention behavior of alkyl-substituted polycyclic aromatic sulfur heterocycles in reversed-phase liquid chromatography.

    PubMed

    Wilson, Walter B; Sander, Lane C; de Alda, Miren Lopez; Lee, Milton L; Wise, Stephen A

    2016-08-26

    Retention indices for 79 alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) were determined by using reversed-phase liquid chromatography (LC) on a monomeric and polymeric octadecylsilane (C18) stationary phase. Molecular shape parameters [length, breadth, thickness (T), and length-to-breadth ratio (L/B)] were calculated for all the compounds studied. Based on separations of isomeric methylated polycyclic aromatic hydrocarbons on polymeric C18 phases, alkyl-substituted PASHs are expected to elute based on increasing L/B ratios. However, the correlation coefficients had a wide range of values from r=0.43 to r=0.93. Several structural features besides L/B ratios were identified to play an important role in the separation mechanism of PASHs on polymeric C18 phases. First, the location of the sulfur atom in a bay-like-region results in alkylated-PASHs being more retentive than non-bay-like-region alkylated-PASHs, and they elute later than expected based on L/B value. Second, the placement of the alkyl group in the k region of the structure resulted in a later elution than predicted by L/B. Third, highly nonplanar methyl-PASHs (i.e., 1-Me and 11-MeBbN12T) elute prior to the parent PASH (BbN12T).

  5. Synthesis and antifungal activities of 3-alkyl substituted thieno[2,3-d]pyrimidinones

    NASA Astrophysics Data System (ADS)

    Wang, H. M.; Deng, S. H.; Zheng, A. H.; Zhang, Q. Y.; Chen, X. B.; Zeng, X. H.; Hu, Y. G.

    2016-08-01

    The 3-aryl substituted thieno[2,3-d]pyrimidinones 3 by sequential reaction of iminophosphorane 1, aromatic isocyanates and various nucleophiles (HY), found some compounds showed good antitumor and antibacterial activities. Meanwhile, aliphatic isocyanates were applied in the reaction to prepare 3-alkyl substituted thieno[2,3- d]pyrimidinones, but there are no reports of their antifungal activities. As a continuation of our research for new biologically active heterocycles, we herein wish to report a facile synthesis and antifungal activities of 3-alkyl substituted thieno[2,3-d]pyrimidinones 6 via easily accessible iminophosphorane 1. The growth inhibitory effect of one concentration (50mg/L) of compounds 6 against five fungus(Fusarium oxysporium, Rhizoctonia solani, Colletotrichum gossypii, Gibberella zeae and Dothiorella gregaria) in vitro was tested by the method of toxic medium. Compound 6d showed the best inhibition rate against Gibberella zeae with 85.68%.

  6. Substitution and addition reactions of •OH with p-substituted-phenols

    NASA Astrophysics Data System (ADS)

    Albarrán, Guadalupe; Galicia-Jiménez, Eduardo; Mendoza, Edith; Schuler, Robert H.

    2017-04-01

    The directing effect of a hydroxyl group on the substitution and addition reactions of •OH to the substituted and free positions in aromatic rings of p-substituted-phenols were studied in aqueous solutions containing either K3Fe(CN)6 as an oxidant of the substituted hydroxycyclohexadienyl radical initially formed or using ascorbic acid. The results showed that the attack of the •OH to the substituted position (ipso position) was followed by elimination of the substituent producing hydroquinone. The addition reaction of the •OH to the free position on the ring produced 4-substituent-catechol and 4-substituent-resorcinol derivatives. Identification and quantification of the radiolytic products were carried out using high performance liquid chromatography. The results of the yields are given for the p-halogen-phenols (p-X-Ph) p-F-Ph, p-Cl-Ph, p-Br-Ph and p-I-Ph. Other compounds, p-nitro-Ph, p-OH-benzoic acid, p-OH-benzonitrile, p-OH-benzaldehyde, p-OH-anisole and p-OH-benzyl alcohol (represented as p-Z-Ph), were only studied using K3Fe(CN)6 as the oxidant. The results show that the p-X-Ph are attacked by the •OH at the ipso position to the halogen in the proportion 1:0.53:0.46:0.11 for F>Cl>Br>I. The •OH attacked at the ipso position to the p-Z-Phs through a substitution reaction, which depended on the substituent group. Thus, the strongly deactivating groups produced less hydroquinone, indicating less substitution reaction than the strongly activating groups.

  7. AgOTf-catalyzed reactions of naphthols/substituted phenols with 2-hydroxychalcones: facile synthesis of di-aromatic ring-fused [3.3.1]bicyclic compounds.

    PubMed

    Rao, Yin; Yin, Guodong

    2013-09-28

    A simple and efficient method for the synthesis of functionalized di-aromatic ring-fused 2,8-dioxabicyclo[3.3.1]nonane derivatives catalyzed by silver triflate from easily available 2-hydroxychalcones and naphthols/substituted phenols is described. Two six-membered cycles were formed in a one-pot operation. This reaction was probably achieved via a Friedel-Crafts alkylation/bicyclization domino process.

  8. Characterization of esterified cassava starch with long alkyl side chains and different substitution degrees.

    PubMed

    Barrios, Simón E; Giammanco, Giuseppe; Contreras, Jesús M; Laredo, Estrella; López-Carrasquero, Francisco

    2013-08-01

    The present work describes the characterization and thermal properties of hydrophobic starch obtained by the esterification of cassava starch with acyl imidazoles, acid chlorides and methyl ester derivatives of fatty acids with n-alkyl chains with 12-22 carbon atoms, in order to compare the dependence of their properties as a function of the length of the side chain and the methodology used for their synthesis. The n-acyl starches presented degrees of substitution (DS) between 0.06 and 1.2. Most of the derivatives obtained with acyl imidazoles were found to be stable at temperatures up to 300°C, whereas those synthesized with acid chlorides or methyl ester decomposed below. Finally, when the n-acyl starches were substituted with n-alkyl side chains of 16 or more carbon atoms, they were capable to crystallize in separate paraffinic phases independent of the starch backbone.

  9. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  10. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  11. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  12. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  13. 40 CFR 721.3810 - Formaldehyde, polymers with substituted phenols (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymers with... New Uses for Specific Chemical Substances § 721.3810 Formaldehyde, polymers with substituted phenols... identified generically as Formaldehyde, polymers with substituted phenols (PMN P-99-0558) is subject...

  14. 40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur...

  15. 40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur...

  16. 40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur...

  17. 40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur...

  18. 40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur...

  19. Hydrothermal conversion of lignin to substituted phenols and aromatic ethers.

    PubMed

    Singh, Rawel; Prakash, Aditya; Dhiman, Shashi Kumar; Balagurumurthy, Bhavya; Arora, Ajay K; Puri, S K; Bhaskar, Thallada

    2014-08-01

    Hydrothermal liquefaction of lignin was performed using methanol and ethanol at various temperatures (200, 250 and 280°C) and residence times of 15, 30 and 45min. Maximum liquid product yield (85%) was observed at 200°C and 15min residence time using methanol. Increase in temperature was seen to decrease the liquid products yield. With increase in residence time, liquid yields first increased and then decreased. FTIR and (1)H NMR showed the presence of substituted phenols and aromatic ethers in liquid products and breakage of β-O-4 or/and α-O-4 ether bonds present in lignin during hydrothermal liquefaction was confirmed through FTIR of bio-residue. In comparison to the existing literature information, higher lignin conversion to liquid products and maximum carbon conversion (72%) was achieved in this study.

  20. Structure-function relationship of substituted bromomethylcoumarins in nucleoside specificity of RNA alkylation.

    PubMed

    Kellner, Stefanie; Kollar, Laura Bettina; Ochel, Antonia; Ghate, Manjunath; Helm, Mark

    2013-01-01

    Selective alkylation of RNA nucleotides is an important field of RNA biochemistry, e.g. in applications of fluorescent labeling or in structural probing experiments, yet detailed structure-function studies of labeling agents are rare. Here, bromomethylcoumarins as reactive compounds for fluorescent labeling of RNA are developed as an attractive scaffold on which electronic properties can be modulated by varying the substituents. Six different 4-bromomethyl-coumarins of various substitution patterns were tested for nucleotide specificity of RNA alkylation using tRNA from Escherichia coli as substrate. Using semi-quantitative LC-MS/MS analysis, reactions at mildly acidic and slightly alkaline pH were compared. For all tested compounds, coumarin conjugates with 4-thiouridine, pseudouridine, guanosine, and uridine were identified, with the latter largely dominating. This data set shows that selectivity of ribonucleotide alkylation depends on the substitution pattern of the reactive dye, and even more strongly on the modulation of the reaction conditions. The latter should be therefore carefully optimized when striving to achieve selectivity. Interestingly, the highest selectivity for labeling of a modified nucleoside, namely of 4-thiouridine, was achieved with a compound whose selectivity was somewhat less dependent on reaction conditions than the other compounds. In summary, bromomethylcoumarin derivatives are a highly interesting class of compounds, since their selectivity for 4-thiouridine can be efficiently tuned by variation of substitution pattern and reaction conditions.

  1. Optimization of alkylating agent prodrugs derived from phenol and aniline mustards: a new clinical candidate prodrug (ZD2767) for antibody-directed enzyme prodrug therapy (ADEPT).

    PubMed

    Springer, C J; Dowell, R; Burke, P J; Hadley, E; Davis, D H; Blakey, D C; Melton, R G; Niculescu-Duvaz, I

    1995-12-22

    Sixteen novel potential prodrugs derived from phenol or aniline mustards and their 16 corresponding drugs with ring substitution and/or different alkylating functionalities were designed. The [[[4-]bis(2-bromoethyl)-(1a), [[[4-[bis(2-iodoethyl)-(1b), and [[[4-[(2-chloroethyl)-[2-(mesyloxy)ethyl]amino]phenyl]oxy] carbonyl]-L-glutamic acids (1c), their [[[2- and 3-substituted-4-[bis(2-chloroethyl)amino]phenyl]oxy]carbonyl]-L- glutamic acids (1e-1), and the [[3-substituted-4-[bis(2-chloroethyl)amino]phenyl]carbamoyl]-L- glutamic acids (1o-r) were synthesized. They are bifunctional alkylating agents in which the activating effect of the phenolic hydroxyl or amino function is masked through an oxycarbonyl or a carbamoyl bond to a glutamic acid. These prodrugs were designed to be activated to their corresponding phenol and aniline nitrogen mustard drugs at a tumor site by prior administration of a monoclonal antibody conjugated to the bacterial enzyme carboxypeptidase G2 (CPG2) in antibody-directed enzyme prodrug therapy (ADEPT). The synthesis of the analogous novel parent drugs (2a-r) is also described. The viability of a colorectal cell line (LoVo) was monitored with the potential prodrugs and the parent drugs. The differential in the cytotoxicity between the potential prodrugs and their corresponding active drugs ranged between 12 and > 195 fold. Compounds 1b-d,f,o exhibited substantial prodrug activity, since a cytotoxicity differential of > 100 was achieved compared to 2b-d,f,o respectively. The ability of the potential prodrugs to act as substrates for CPG2 was determined (kinetic parameters KM and kcat), and the chemical stability was measured for all the compounds. The unsubstituted phenols with different alkylating functionalities (1a-c) proved to have the highest ratio of the substrates kcat:KM. From these studies [[[4-[bis(2-iodoethyl)amino]phenyl]oxy]carbonyl]-L-glutamic acid (1b) emerges as a new ADEPT clinical trial candidate due to its physicochemical and

  2. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic). Link to an amendment published at 79 FR 34637, June 18, 2014. (a) Chemical substance and significant new uses subject to reporting. (1)...

  3. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  4. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  5. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  6. 40 CFR 721.3830 - Formaldehyde, reaction products with an alkylated phenol and an aliphatic amine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Formaldehyde, reaction products with... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3830 Formaldehyde, reaction..., reaction products with an alkylated phenol and an aliphatic amine (PMN P-99-0531) is subject to...

  7. 40 CFR 721.3488 - Poly(oxy-1,2-ethanediyl), alpha substituted-omega-hydroxy-, C16-20 alkyl ethers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted-omega-hydroxy-, C16-20 alkyl ethers. 721.3488 Section 721.3488 Protection of Environment... substituted-omega-hydroxy-, C16-20 alkyl ethers. (a) Chemical substance and significant new uses subject to...-omega-hydroxy-, C16-20 alkyl ethers (PMN P-87-323) is subject to reporting under this section for...

  8. 40 CFR 721.3488 - Poly(oxy-1,2-ethanediyl), alpha substituted-omega-hydroxy-, C16-20 alkyl ethers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted-omega-hydroxy-, C16-20 alkyl ethers. 721.3488 Section 721.3488 Protection of Environment... substituted-omega-hydroxy-, C16-20 alkyl ethers. (a) Chemical substance and significant new uses subject to...-omega-hydroxy-, C16-20 alkyl ethers (PMN P-87-323) is subject to reporting under this section for...

  9. 40 CFR 721.3488 - Poly(oxy-1,2-ethanediyl), alpha substituted-omega-hydroxy-, C16-20 alkyl ethers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted-omega-hydroxy-, C16-20 alkyl ethers. 721.3488 Section 721.3488 Protection of Environment... substituted-omega-hydroxy-, C16-20 alkyl ethers. (a) Chemical substance and significant new uses subject to...-omega-hydroxy-, C16-20 alkyl ethers (PMN P-87-323) is subject to reporting under this section for...

  10. 40 CFR 721.3488 - Poly(oxy-1,2-ethanediyl), alpha substituted-omega-hydroxy-, C16-20 alkyl ethers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted-omega-hydroxy-, C16-20 alkyl ethers. 721.3488 Section 721.3488 Protection of Environment... substituted-omega-hydroxy-, C16-20 alkyl ethers. (a) Chemical substance and significant new uses subject to...-omega-hydroxy-, C16-20 alkyl ethers (PMN P-87-323) is subject to reporting under this section for...

  11. 40 CFR 721.3488 - Poly(oxy-1,2-ethanediyl), alpha substituted-omega-hydroxy-, C16-20 alkyl ethers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted-omega-hydroxy-, C16-20 alkyl ethers. 721.3488 Section 721.3488 Protection of Environment... substituted-omega-hydroxy-, C16-20 alkyl ethers. (a) Chemical substance and significant new uses subject to...-omega-hydroxy-, C16-20 alkyl ethers (PMN P-87-323) is subject to reporting under this section for...

  12. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  13. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  14. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  15. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  16. 40 CFR 721.9220 - Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... amines with a substituted benzenesulfonic acid and sulfuric acid (generic name). 721.9220 Section 721... Reaction products of secondary alkyl amines with a substituted benzenesulfonic acid and sulfuric acid... benzenesulfonic acid and sulfuric acid (PMNs P-89-703, P-89-755, and P-89-756) are subject to reporting under...

  17. C5-Alkyl-2-methylurea-Substituted Pyridines as a New Class of Glucokinase Activators

    PubMed Central

    2014-01-01

    Glucokinase (GK) activators represent a class of type 2 diabetes therapeutics actively pursued due to the central role that GK plays in regulating glucose homeostasis. Herein we report a novel C5-alkyl-2-methylurea-substituted pyridine series of GK activators derived from our previously reported thiazolylamino pyridine series. Our efforts in optimizing potency, enzyme kinetic properties, and metabolic stability led to the identification of compound 26 (AM-9514). This analogue showed a favorable combination of in vitro potency, enzyme kinetic properties, acceptable pharmacokinetic profiles in preclinical species, and robust efficacy in a rodent PD model. PMID:25516785

  18. Fourier-transform microwave spectroscopy of an alkyl substituted Criegee intermediate anti-CH3CHOO

    NASA Astrophysics Data System (ADS)

    Nakajima, Masakazu; Yue, Qiang; Endo, Yasuki

    2015-04-01

    Pure rotational transitions of the anti-form of the simplest alkyl-substituted Criegee intermediate, anti-CH3CHOO, were observed by Fourier-transform microwave spectroscopy. The observed transition frequencies in the A and E levels of the ground vibrational state were analyzed together, and molecular constants including parameters which characterize the internal rotation of the methyl rotor were determined. The experimentally determined barrier height of the three-fold potential for the methyl internal rotation is 399.1 cm-1, less than a half of that of the other conformer, syn-CH3CHOO (Nakajima and Endo, 2014).

  19. Antioxidant effectiveness generated by one or two phenolic hydroxyl groups in coumarin-substituted dihydropyrazoles.

    PubMed

    Xi, Gao-Lei; Liu, Zai-Qun

    2013-10-01

    A cascade operation was designed to synthesize nine coumarin-substituted dihydropyrazoles with only one or two phenolic hydroxyl groups contained. Antioxidant abilities of the obtained compounds were evaluated by inhibiting 2,2'-azobis(2-amidinopropanehydrochloride) (AAPH)-, Cu2+/glutathione (GSH)-, and .OH-induced oxidation of DNA. It was found that less phenolic hydroxyl groups can enhance the abilities of coumarin-substituted dihydropyrazoles to protect DNA against the oxidation. Moreover, these coumarin-substituted dihydropyrazoles were employed to scavenge 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS+.), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that double phenolic hydroxyl groups were more beneficial for enhancing the abilities of coumarin-substituted dihydropyrazoles to quench the aforementioned radicals. Therefore, dihydropyrazole linked with coumarin exhibited powerful antioxidant effectiveness even in the case of less phenolic hydroxyl groups involved.

  20. Integrated catalytic and electrocatalytic conversion of substituted phenols and diaryl ethers

    SciTech Connect

    Song, Yang; Chia, Shao H.; Sanyal, Udishnu; Gutierrez, Oliver Y.; Lercher, Johannes A.

    2016-10-17

    Electrocatalytic hydrogenation and catalytic thermal hydrogenation of substituted phenols and diaryl ethers were studied on carbon-supported Rh. For electrocatalytic and catalytic thermal hydrogen addition reactions, the dominant reaction pathway is hydrogenation to cyclic alcohols and cycloalkyl ethers. The presence of substituting methyl or methoxy groups led to lower rates compared to unsubstituted phenol or diphenyl ether. Methoxy or benzyloxy groups, however, undergo C-O bond cleavage via hydrogenolysis and hydrolysis (minor pathway).

  1. The replacement of alkyl-phenol ethoxylates to improve the environment acceptability of drilling fluid additives

    SciTech Connect

    Getliff, J.M.; James, S.G.

    1996-12-31

    Alkyl-phenol ethoxylates (APEO) are a class of surfactants which have been used widely in the drilling fluid industry. The popularity of these surfactants is based on their cost effectiveness, availability and the range of hydrophilic-lipophilic balance values obtainable. Studies have shown that APEOs exhibit oestrogenic effects, and can cause sterility in some male aquatic species. This may have subsequent human consequences and such problems have lead to a banning of their use in some countries and agreements to phase out their use e.g. PARCOM recommendation 92/8. The use of APEOs as additives in detergents, lubricants and stuck-pipe release agents for drilling fluid applications is discussed. The effectiveness of products formulated with APEOs are directly compared with alternative products which are non-persistent and less damaging to aquatic species. Lubricity measurements using standard and in-house designed equipment and washing tests to compare the efficiency of surfactants are explained and product performance results presented. The results show that alternatives to products containing APEOs are available and that in some cases they show a better technical performance. In addition to the improved environmental acceptability of the base chemicals, the better performance enables lower concentrations to be used, hence reducing the environmental impact even further.

  2. The effect of varying short-chain alkyl substitution on the molar absorptivity and quantum yield of cyanine dyes.

    PubMed

    Chapman, Gala; Henary, Maged; Patonay, Gabor

    2011-01-01

    The effect of varying short-chain alkyl substitution of the indole nitrogens on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and fluorescence quantum yields were determined for a set of pentamethine dyes and a set of heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length resulted in no significant change in quantum yield or molar absorptivity. These results may be useful in designing new cyanine dyes for analytical applications and predicting their spectroscopic properties.

  3. Influence of structural and solvation factors on the spectral-fluorescent properties of alkyl-substituted BODIPYs in solutions

    NASA Astrophysics Data System (ADS)

    Bumagina, Natalia A.; Antina, Elena V.; Berezin, Mikhail B.; Kalyagin, Alexander A.

    2017-02-01

    The spectral-fluorescent properties of alkyl-substituted BODIPYs 1-5 in organic solvents were investigated. The alkyl-substituted BODIPYs 1-5 exhibit intense chromophoric properties (lgε = 4.60-5.00). Relative fluorescence quantum yield of studied compounds reaches 66-100% and weakly dependent on the structural and solvation effects. Introduction of methyl, propyl, amyl and heptyl substituents in the 2,6-positions of the pyrroles the results in a significant red shift (22-29 nm) in the electronic absorption and fluorescence spectra.

  4. ABTS as an Electron Shuttle to Enhance the Oxidation Kinetics of Substituted Phenols by Aqueous Permanganate.

    PubMed

    Song, Yang; Jiang, Jin; Ma, Jun; Pang, Su-Yan; Liu, Yong-Ze; Yang, Yi; Luo, Cong-Wei; Zhang, Jian-Qiao; Gu, Jia; Qin, Wen

    2015-10-06

    In this study, it was, interestingly, found that 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonate (ABTS), a widely used electron shuttle, could greatly accelerate the oxidation of substituted phenols by potassium permanganate (Mn(VII)) in aqueous solutions at pH 5-9. This was attributed to the fact that these substituted phenols could be readily oxidized by the stable radical cation (ABTS(•+)), which was quickly produced from the oxidation of ABTS by Mn(VII). The reaction of Mn(VII) with ABTS exhibited second-order kinetics, with stoichiometries of ∼5:1 at pH 5-6 and ∼3:1 at pH 7-9, and the rate constants varied negligibly from pH 5 to 9 (k = (9.44 ± 0.21) × 10(4) M(-1) s(-1)). Comparatively, the reaction of ABTS(•+) with phenol showed biphasic kinetics. The second-order rate constants for the reactions of ABTS(•+) with substituted phenols obtained in the initial phase were strongly affected by pH, and they were several orders of magnitude higher than those for the reactions of Mn(VII) with substituted phenols at each pH. Good Hammett-type correlations were found for the reactions of ABTS(•+) with undissociated (log(k) = 2.82-4.31σ) and dissociated phenols (log(k) = 7.29-5.90σ). The stoichiometries of (2.2 ± 0.06):1 (ABTS(•+) in excess) and (1.38 ± 0.18):1 (phenol in excess) were achieved in the reaction of ABTS(•+) with phenol, but they exhibited no pH dependency.

  5. Characterization of Substituted Phenol-Formaldehyde Resins Using Solid-State Carbon-13 NMR

    DTIC Science & Technology

    1989-05-22

    synthesized from cashew nut shell liquid, 3-n-pentadecylphenol and phenol with formaldehyde. The resulting resins were crosslinked and then investigated using...should be sent SYNOPSIS Crosslinked substituted phenol-formaldehyde resins were synthesized from cashew nut shell liquid, 3-n-pentadecylphenol and... nut shell liquid (CNSL) and are the basis for binder resins and friction particles in composite friction materials. CNSL is isolated from cashew nut

  6. Multistep conversion of para-substituted phenols by phenol hydroxylase and 2,3-dihydroxybiphenyl 1,2-dioxygenase.

    PubMed

    Qu, Yuanyuan; Shi, Shengnan; Ma, Qiao; Kong, Chunlei; Zhou, Hao; Zhang, Xuwang; Zhou, Jiti

    2013-04-01

    A multistep conversion system of para-substituted phenols by recombinant phenol hydroxylase (PH(IND)) and 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC(LA-4)) was constructed in this study. Docking studies with different para-substituted phenols and corresponding catechols inside of the active site of PH(IND) and BphC(LA-4) predicted that all the substrates should be transformed. High-performance liquid chromatography-mass spectrometry analysis showed that the products of multistep conversion were the corresponding para-substituted catechols and semialdehydes. For the first-step conversion, the formation rate of 4-fluorocatechol (0.39 μM/min/mg dry weight) by strain PH(IND) hydroxylation was 1.15, 6.50, 3.00, and 1.18-fold higher than the formation of 4-chlorocatechol, 4-bromocatechol, 4-nitrocatechol, and 4-methylcatechol, respectively. For the second-step conversion, the formation rates of semialdehydes by strain BphC(LA-4) were as follows: 5-fluoro-HODA>5-chloro-HODA>2-hydroxy-5-nitro-ODA>5-bromo-HODA>2-hydroxy-5-methyl-ODA. The present study suggested that the multistep conversion by both ring hydroxylase and cleavage dioxygenase should be potential in the synthesis of industrial precursors and provide a novel avenue in the wastewater recycling treatment.

  7. Evaluation of the α-phenylvinyl cation as a chemical ionization reagent for the differentiation of isomeric substituted phenols in an ITMS.

    PubMed

    Begala, Michela

    2015-04-01

    Ion-molecule reactions between the α-phenylvinyl cation and isomeric naturally occurring phenols were investigated using a quadruple ion trap mass spectrometer. The α-phenylvinyl cation m/z 103, generated by chemical ionization from phenylacetylene, reacts with neutral aromatic compounds to form the characteristic species: [M + 103](+) adduct ions and the trans-vinylating product ions [M + 25](+) , which correspond to [M + 103](+) adduct after the loss of benzene. Isomeric differentiation of several ring-substituted phenols was achieved by using collision-induced dissociation of the [M + 103](+) adduct ions. This method also showed to be effective in the differentiation of 4-ethylguaiacol from one of its structural isomers that displays identical EI and EI/MS/MS spectra. The effects of gas-phase alkylation with phenylvinyl cation on the dissociation behavior were examined using mass spectrometry(n) and labeled derivatives. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Correlation of antimutagenic activity and suppression of CYP1A with the lipophilicity of alkyl gallates and other phenolic compounds.

    PubMed

    Feng, Qing; Kumagai, Takeshi; Nakamura, Yoshimasa; Uchida, Koji; Osawa, Toshihiko

    2003-05-09

    Alkyl gallates are widely used as food antioxidants. Methyl, ethyl, propyl, lauryl, and cetyl gallates showed antimutagenicity to activated 2-aminoanthracene (2AA)-induced SOS responses in Salmonella typhimurium TA1535/pSK1002. They also exhibited a suppressive effect on 3-methylcholanthrene (3-MC)-induced cytochrome P450 1A (CYP1A) in human hepatoma HepG2 cells, as indexed by the 7-ethoxyresorufin-O-deethylase (EROD) activity, and on CYP1A protein level. Both antimutagenicity and suppression of CYP1A appeared to be dependent on alkyl chain lengths, which suggested lipophilicity dependence. Based on those results, we investigated 26 other phenolic compounds for their lipophilicity, antimutagenicity and inhibition of EROD activity. The lipophilicity correlated well with the inhibition of EROD activity (r=0.78), and the inhibition of EROD activity correlated with the antimutagenicity of those compounds (r=0.71). The results suggest that the lipophilicity of the phenolic compounds may be an important factor in their ability to inhibit EROD activity.

  9. Indole and its alkyl-substituted derivatives protect erythrocyte and DNA against radical-induced oxidation.

    PubMed

    Zhao, Feng; Liu, Zai-Qun

    2009-01-01

    The antioxidant properties of 1,2,3,4-tetra-hydrocarbazole, 6-methoxy-1,2,3,4-tetrahydrocar-bazole (MTC), 2,3-dimethylindole, 5-methoxy-2,3-dimethylindole, and indole were investigated in the case of hemolysis of human erythrocytes and oxidative damage of DNA induced by 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), respectively. The aim of this work was to explore the influence of methoxy, methyl, and cyclohexyl substituents on the antioxidant activities of indole derivatives. These indole derivatives were able to protect erythrocytes and DNA in a concentration-dependent manner. The alkyl-substituted indole can protect erythrocytes and DNA against AAPH-induced oxidation. Especially, the structural features of cyclohexyl and methoxy substituents made MTC the best antioxidant among the indole derivatives used herein. Finally, the interaction between these indole derivatives and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation and 2,2'-diphenyl-1-picrylhydrazyl, respectively, provided direct evidence for these indole derivatives to scavenge radicals and emphasized the importance of electron-donating groups for the free radical-scavenging activity of indole derivatives.

  10. Oxidation and thermolysis of methoxy-, nitro-, and hydroxy-substituted phenols in supercritical water

    SciTech Connect

    Martino, C.J.; Savage, P.E.

    1999-05-01

    The authors have examined the oxidative decomposition of m- and p-methoxyphenol, m-, and p-nitrophenol, and resorcinol and the nonoxidative decomposition of o-, m- and p-methoxyphenol in dilute aqueous solutions at 460 C and 25.3 MPa for residence times on the order of 5 s. The major products from methoxyphenol decomposition in the absence of added oxygen are phenol and hydroxyphenols. The thermolysis kinetics can be described by a power-law rate equation with a reaction order between 0.5 and 1.0, which is consistent with previous studies done at different reaction conditions. Comparing the thermolysis rates for methoxyphenols with those of other substituted phenols showed that the rates are sensitive to both the identity and the location of the substituent. For a given substituent location, NO{sub 2}-substituted phenols reacted more rapidly than either CHO- or OCH{sub 3}-substituted phenols. Additionally, the ortho isomer was always the most reactive. Phenol is a product of incomplete oxidation from the methoxy-phenols and nitrophenols, but no phenol was observed when resorcinol was oxidized. The oxidation kinetics were correlated with power-law rate expressions. The experiments and subsequent kinetics analysis allowed them to separate and quantify the rates of thermolysis and oxidation individually. A comparison of these reactant disappearance rates shows that thermolysis accounts for about 5% of the total rate for m- and p-methoxyphenol during oxidation in supercritical water. Thermolysis accounts for up to 25% of the total rate for m- and p-nitrophenols.

  11. Study of charge transfer complexes of [70]fullerene with phenol and substituted phenols.

    PubMed

    Bhattacharya, Sumanta; Banerjee, Shrabanti; Banerjee, Manas

    2005-07-01

    To improve the understanding of the charge transfer (CT) interaction of [70]fullerene with electron donors, interaction of [70]fullerene with a series of phenols, e.g., phenol, resorcinol and p-quinol were studied in 1,4-dioxan medium using absorption spectroscopy. An absorption band due to CT transition was observed in the visible region. The experimental CT transition energies (h nuCT) are well correlated (through Mulliken's equation) with the vertical ionisation potentials (I(D)v) of the series of phenols studied. From an analysis of this correlation degrees of charge transfer for the [70]fullerene-phenol complexes were estimated. The degrees of charge transfer in the ground state of the complexes have been found to be very low (<2%). The h nuCT values change systematically as the number and position of the -OH groups change on the aromatic ring of the phenol moiety. From the trends in the h nuCT values, the Hückel parameters (h(O) and k(C-O)) for the -OH group were obtained in a straightforward way and the values so obtained, viz., 1.91 and 1.0, respectively, are close to the ones (1.8 and 0.8) recommended by Streitwieser on the basis of other evidence. Oscillator strengths, transition dipole strengths and resonance energies of the [70]fullerene-phenol complexes were determined. Formation constants of the CT complexes were determined at four different temperatures from which enthalpies and entropies of formation of the complexes were estimated.

  12. Enzymic aromatization of 6-alkyl-substituted androgens, potent competitive and mechanism-based inhibitors of aromatase.

    PubMed

    Numazawa, M; Yoshimura, A; Oshibe, M

    1998-01-01

    To gain insight into the relationships between the aromatase inhibitory activity of 6-alkyl-substituted androgens, potent competitive inhibitors, and their ability to serve as a substrate of aromatase, we studied the aromatization of a series of 6alpha- and 6beta-alkyl (methyl, ethyl, n-propyl, n-pentyl and n-heptyl)-substituted androst-4-ene-3,17-diones (ADs) and their androsta-1,4-diene-3,17-dione (ADD) derivatives with human placental aromatase, by gas chromatography-mass spectrometry. Among the inhibitors examined, ADD and its 6alpha-alkyl derivatives with alkyl functions less than three carbons long, together with 6beta-methyl ADD, are suicide substrates of aromatase. All of the steroids, except for 6beta-n-pentyl ADD and its n-heptyl analogue as well as 6beta-n-heptyl AD, were found to be converted into the corresponding 6-alkyl oestrogens. The 6-methyl steroids were aromatized most efficiently in each series, and the aromatization rate essentially decreased in proportion to the length of the 6-alkyl chains in each series, where the 6alpha-alkyl androgens were more efficient substrates than the corresponding 6beta isomers. The Vmax of 6alpha-methyl ADD was approx. 2.5-fold that of the natural substrate AD and approx. 3-fold that of the parent ADD. On the basis of this, along with the facts that the rates of a mechanism-based inactivation of aromatase by ADD and its 6alpha-methyl derivative are similar, it is implied that alignment of 6alpha-methyl ADD in the active site could favour the pathway leading to oestrogen over the inactivation pathway, compared with that of ADD. The relative apparent Km values for the androgens obtained in this study are different from the relative Ki values obtained previously, indicating that there is a difference between the ability to serve as an inhibitor and the ability to serve as a substrate in the 6-alkyl androgen series.

  13. Enantioselective sp(3) C-H alkylation of γ-butyrolactam by a chiral Ir(I) catalyst for the synthesis of 4-substituted γ-amino acids.

    PubMed

    Tahara, Yu-ki; Michino, Masamichi; Ito, Mamoru; Kanyiva, Kyalo Stephen; Shibata, Takanori

    2015-12-04

    Ir-catalyzed sp(3) C-H alkylation of γ-butyrolactam with alkenes was used for the highly enantioselective synthesis of 5-substituted γ-lactams, which were readily converted into chiral 4-substituted γ-amino acids. A broad scope of alkenes was amenable as coupling partners, and the alkylated product using acrylate could be transformed into the key intermediate of pyrrolam A synthesis.

  14. Ytterbium(III) triflate catalyzed tandem Friedel-Crafts alkylation/hydroarylation of propargylic alcohols with phenols as an expedient route to indenols.

    PubMed

    Zhang, Xiaoxiang; Teo, Wan Teng; Chan, Philip Wai Hong

    2009-11-05

    A method to prepare indenols efficiently by ytterbium(III) triflate catalyzed tandem Friedel-Crafts alkylation/hydroarylation of propargylic alcohols with phenols is described. The reaction was accomplished in moderate to excellent yields and regioselectivity under mild conditions and offers a straightforward and convenient one step synthetic route to bioactive indenols and its derivatives.

  15. UV spectroscopic characterization of an alkyl substituted Criegee intermediate CH3CHOO.

    PubMed

    Beames, Joseph M; Liu, Fang; Lu, Lu; Lester, Marsha I

    2013-06-28

    Ozonolysis of alkenes in the troposphere proceeds through a Criegee intermediate, or carbonyl oxide, which has only recently been detected in the gas phase. The present study focuses on the production of an alkyl-substituted Criegee intermediate, CH3CHOO, in a pulsed supersonic expansion, and then utilizes VUV photoionization at 118 nm and UV-induced depletion of the m∕z = 60 signal to probe the B (1)A(') ← X (1)A(') transition. The UV-induced depletion approaches 100% near the peak of the profile at 320 nm, indicating rapid dynamics in the B state, and corresponds to a peak absorption cross section of ∼5 × 10(-17) cm(2) molecule(-1). The electronic spectrum for CH3CHOO is similar to that reported recently for CH2OO, but shifted 15 nm to shorter wavelength, which will result in a longer tropospheric lifetime for CH3CHOO with respect to solar photolysis. Complementary electronic structure calculations (EOM-CCSD) are carried out for the B and X potentials of these Criegee intermediates along the O-O coordinate. An intramolecular interaction stabilizes the ground state of the syn-conformer of CH3CHOO relative to anti-CH3CHOO, and indicates that the syn-conformer will be the more abundant species in the expansion. The excited B electronic state of syn-CH3CHOO is also predicted to be destabilized relative to that for anti-CH3CHOO and CH2OO, in accord with the shift in the B-X transition observed experimentally. Hydroxyl radicals produced concurrently with the generation of the Criegee intermediates are detected by 1+1(') resonance enhanced multiphoton ionization. The OH yield observed with CH3CHOO is 4-fold larger than that from CH2OO, consistent with prior studies of OH generation from alkene ozonolysis.

  16. Inhibition of biogas production and biodegradability by substituted phenolic compounds in anaerobic sludge.

    PubMed

    Hernandez, J E; Edyvean, R G J

    2008-12-15

    Phenolic compounds are abundant in nature and organic wastes. This biomass may be utilised in biogas generation. Phenolics can inhibit the degradation of readily biodegradable organic fractions and their own biodegradation. In this work, assays were carried out under anaerobic conditions to study the inhibition of both gas production and biodegradability due to seven phenolic compounds and to study their adsorption onto sludge and autoxidation in the aqueous medium. Fifty percent inhibition was in the range of 120 to 594 mg of compound/g VSS. An initial enhancement followed by an inhibition of biogas formation was found. The inhibition by the phenolic compounds was found to be influenced by autoxidation, apolarity, type, size and number of substitutions. Biogas production is influenced by concentration rather than any pH change. The concentration of the phenolic compound was partially biomethanized and the degradation of gallic and caffeic acids by this process is reported here for the first time. The maximum total biodegradation of any phenolic compound was 63.85+/-2.73%, and remaining non-biodegradable fraction was autoxidized and adsorbed onto the sludge matrix. Inhibition of methanization and partial inhibition of background gas was found at concentrations between 800 and 1600 mg/L organic carbon.

  17. Emission spectra of the cations of some fluoro-substituted phenols in the gaseous phase

    USGS Publications Warehouse

    Maier, John Paul; Marthaler, O.; Mohraz, Manijeh; Shiley, R.H.

    1980-01-01

    Emission spectra of the cations of 2,5- and 3,5-difluorophenol, of 2,3,4- and 2,4,5-trifluorophenol, of 2,3,5,6-tetrafluorophenol and of 2,3,4,5,6-pentafluorophenol have been obtained in the gas phase using low-energy electron beam excitation. The band systems are assigned to the B??(??-1) ??? X??(??-1) electronic transitions of these cations by reference to photoelectron spectroscopic data. The He(I??) photoelectron spectra and the ionisation energies of ten fluoro-substituted phenols are reported. The symmetries of the four lowest electronic states of these cations are inferred from the radiative decay studies. The lifetimes of the lowest vibrational levels of the B??(??-1) state of the six fluoro-substituted phenol cations above have also been measured. ?? 1980.

  18. The effect of N-substituted alkyl groups on the anticonvulsant activities ofN-Cbz-alpha-amino-N-alkylsuccinimides.

    PubMed

    Lee, J; Son, K; Jung, K; Choi, J; Park, M

    1997-02-01

    For the purpose of defining the effects of theN-substituted alkyl groups on the anticonvulsant activities ofN-Cbz-alpha-aminosuccinimides, various (R)-and(S)-N-alkyl substitutedN-Cbz-alpha-aminosuccinimides (1 and2) were prepared from the corresponding (R)-and(S)-N-Cbz-aspartic acid by using known reaction and were evaluated the anticonvulsant activies in the MES and PTZ tests, including their neurotoxicities. The most active compound in the MES test was(R)-N-Cbz-alpha-amino-N-methylsuccinimide (1b) (ED(50)=52.5 mg/kg, Pl-3.2). And in case of the PTZ test,(R)-N-Cbz-alpha-amino-N-ethylsuccinimide (1c) was the most active compound (ED(50)=32.5 mg/kg, Pl=3.1). The order of anticonvulsant activities of these compounds against the MES test, as judged from the ED(50) values for theR series (1), wasN-methyl >N-isobutyl > non-substituted >N-ethyl,N-allyl >N-benzyl compound; for theS series (2)N-methyl >N-allyl > non-substituted >N-isobutyl >N-ethyl >N-benzyl compound. The anticonvulsant activities in the PTZ tests of these compounds exhibited somewhat different pattern; for theR series (1)N-ethyl >N-methyl >N-isobutyl> non-substituted >N-allyl >N-benzyl compound in order of decreasing activity; forS series (2)N-ethyl >N-allyl, non-substituted >N-isobutyl >N-methyl >N-benzyl compound in order of decreasing activity.

  19. Mass-analyzed threshold ionization spectroscopy of p-methylphenol and p-ethylphenol cations and the alkyl substitution effect

    NASA Astrophysics Data System (ADS)

    Lin, Jung Lee; Li, Changyong; Tzeng, Wen Bih

    2004-06-01

    The mass-analyzed threshold ionization (MATI) spectra of p-methylphenol and p-ethylphenol have been recorded by ionizing via various vibronic levels. The adiabatic ionization energies (IEs) of p-methylphenol and p-ethylphenol are determined to be 65918±5 and 65628±5 cm-1, which are less than that of phenol by 2707 and 2997 cm-1, respectively. This redshift indicates that the interaction between the alkyl group and the ring of alkylphenols in the cationic D0 state is greater than that in the neutral S0 state. Moreover, a longer alkyl group gives rise to a greater redshift in the IE. Analysis of the MATI spectra shows that most of the active modes are related to the in-plane ring vibrations of these two cations. However, the length of the alkyl group has an insignificant effect on the frequency of the observed ring vibrations. No band with frequency less than 350 cm-1 is observed for the p-methylphenol cation. In contrast, many low-frequency bands resulting from the characteristic motions (e.g., the C-C2H5 torsion and C-C2H5 and C-OH bending vibrations) appear in the MATI spectra of p-ethylphenol. The present results show that the ethyl group enhances the substituent-sensitive and many large-amplitude vibrations of the cation.

  20. pi-Selective stationary phases: (II) Adsorption behavior of substituted aromatic compounds on n-alkyl-phenyl stationary phases

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A; Mayfield, Kirsty; Dennis, Gary; Shalliker, R. Andrew

    2010-01-01

    The frontal analysis method was used to measure the adsorption isotherms of phenol, 4-chlorophenol, p-cresol, 4-methoxyphenol and caffeine on a series of columns packed with home-made alkyl-phenyl bonded silica particles. These ligands consist of a phenyl ring tethered to the silica support via a carbon chain of length ranging from 0 to 4 atoms. The adsorption isotherm models that fit best to the data account for solute-solute interactions that are likely caused by p-p interactions occurring between aromatic compounds and the phenyl group of the ligand. These interactions are the dominant factor responsible for the separation of low molecular weight aromatic compounds on these phenyl-type stationary phases. The saturation capacities depend on whether the spacer of the ligands have an even or an odd number of carbon atoms, with the even alkyl chain lengths having a greater saturation capacity than the odd alkyl chain lengths. The trends in the adsorption equilibrium constant are also significantly different for the even and the odd chain length ligands.

  1. Aqueous adsorption of aniline, phenol, and their substitutes by multi-walled carbon nanotubes.

    PubMed

    Yang, Kun; Wu, Wenhao; Jing, Qingfeng; Zhu, Lizhong

    2008-11-01

    Aqueous adsorption of a series of phenols and anilines by a multiwalled carbon nanotube material (MWCNT15), which depends strongly on the solution pH and the number and types of solute groups, was investigated in this study. The pH-dependent adsorption coefficients, Kd, could be predicted by the established models including solute pKa and solution pH values. Phenol or aniline substitution with more groups has higher adsorption affinity, and nitro, chloride, or methyl groups enhanced adsorption in the following order: nitro group > chloride group > methyl group. All adsorption isotherms of nondissociated phenols and anilines are nonlinear and fitted well bythe Polanyi-theory based Dubinin-Ashtakhov (DA) model. Linear quantitative relationships combining DA model parameters (E and b) with solute solvatochromic parameters were developed to evaluate the adsorptive behaviors of nondissociated species. For the saturated sorbed capacity, Q0, the logarithmic values of phenols and anilines were relatively constant with a mean value of 1.90. Besides the van der Waals force, H-bonding interactions from solutes as hydrogen-bonding donors, and followed by pi-electron polarizability, may play important roles on the adsorption of phenols and anilines by carbon nanotubes in the aqueous environment

  2. Ligand substitution reactions of a phenolic quinolyl hydrazone; oxidovanadium (IV) complexes

    PubMed Central

    2011-01-01

    Background Quinoline ring has therapeutic and biological activities. Quinolyl hydrazones constitute a class of excellent chelating agents. Recently, the physiological and biological activities of quinolyl hydrazones arise from their tendency to form metal chelates with transition metal ions. In this context, we have aimed to study the competency effect of a phenolic quinolyl hydrazone (H2L; primary ligand) with some auxiliary ligands (Tmen, Phen or Oxine; secondary ligands) towards oxidovanadium (IV) ions. Results Mono- and binuclear oxidovanadium (IV) - complexes were obtained from the reaction of a phenolic quinolyl hydrazone with oxidovanadium (IV)- ion in absence and presence of N,N,N',N'- tetramethylethylenediamine (Tmen), 1,10-phenanthroline (Phen) or 8-hydroxyquinoline (Oxine). The phenolic quinolyl hydrazone ligand behaves as monobasic bidentate (NO- donor with O- bridging). All the obtained complexes have the preferable octahedral geometry except the oxinato complex (2) which has a square pyramid geometry with no axial interaction; the only homoleptic complex in this study. Conclusion The ligand exchange (substitution/replacement) reactions reflect the strong competency power of the auxiliary aromatic ligands (Phen/Oxine) compared to the phenolic quinolyl hydrazone (H2L) towards oxidovanadium (IV) ion; (complexes 2 and 3). By contrast, in case of the more flexible aliphatic competitor (Tmen), an adduct was obtained (4). The obtained complexes reflect the strength of the ligand field towards the oxidovanadium (IV)- ion; Oxine or Phen >> phenolic hydrazone (H2L) > Tmen. PMID:21846387

  3. Thermohalochromism of phenolate dyes conjugated with nitro-substituted aryl groups

    NASA Astrophysics Data System (ADS)

    Hermosilla, Laura; Rezende, Marcos Caroli; Machado, Vanderlei Gageiro; Stock, Rafaela I.

    2017-02-01

    The cationic halochromism and thermohalochromism of four phenolate dyes conjugated with aryl moieties substituted with one or two nitro groups were investigated in the presence of organic (tetra-n-butylammonium bromide and benzyltriethylammonium chloride) and inorganic (sodium perchlorate) salts, in hydrogen-bond donating (water, 1-propanol, 1-butanol and 2-propanol) and hydrogen-bond accepting (acetonitrile and dimethylsulfoxide) solvents. Although a positive halochromic response was observed in water for tetraalkylammonium salts, their thermohalochromic behavior was negligible. A negative halochromic behavior was observed for the dyes in all solvents, when the added cation was Na+. Plots of Δλmaxvs. c (Na+) allowed the apparent association constants for the solvated phenolate-cation pair to be estimated. In most cases, a positive thermohalochromism was observed in the range of 25-50 °C, exceptions being the more sterically hindered phenolate dyes in the less polar solvents 2-propanol and acetonitrile. The observed variations were rationalized by invoking the effect of temperature on the phenolate-cation, phenolate-solvent and cation-solvent interactions.

  4. Ion-pair association of substituted phenolates with K{sup +} in octanol

    SciTech Connect

    Strathmann, T.J.; Jafvert, C.T.

    1998-03-01

    The speciation, environmental distribution, and ultimate fate of phenolic compounds, a class of hydrophobic ionizable organic compounds, is influenced by both their hydrophobic and electrostatic characteristics. In this study, electrical conductance measurements were employed to characterize the ion-pair association properties of a monovalent inorganic cation (K{sup +}) with substituted phenolate anions in the model hydrophobic solvent, 1-octanol. Quantification of such processes is important for characterizing the overall partitioning to and speciation in octanol of phenolic compounds. Data were analyzed and association constants were calculated using a modified form of the Fuoss-Onsager equation for electrical conductivity. Results indicate that the magnitude of ion-pair association correlates with the electron-donating and -withdrawing characteristics of phenolic ring substituents. A quantitative structure-activity relationship was developed correlating ion-pair association constants to the sum of Hammett substituent constants for each species. The data suggest that for some phenolate salts, charged triple ion or higher aggregate formation may occur at elevated concentrations. A qualitative interpretation of this phenomenon and the selectivity of its occurrence are discussed.

  5. Copper (II) complexes possessing alkyl-substituted polypyridyl ligands: Structural characterization and in vitro antitumor activity.

    PubMed

    Angel, Noah R; Khatib, Raneen M; Jenkins, Julia; Smith, Michelle; Rubalcava, Justin M; Le, Brian Khoa; Lussier, Daniel; Chen, Zhuo Georgia; Tham, Fook S; Wilson, Emma H; Eichler, Jack F

    2017-01-01

    In an effort to find alternatives to the antitumor drug cisplatin, a series of copper (II) complexes possessing alkyl-substituted polypyridyl ligands have been synthesized. Eight new complexes are reported herein: μ-dichloro-bis{2,9-di-sec-butyl-1,10-phenanthrolinechlorocopper(II)} {[((di-sec-butyl)phen)ClCu(μ-Cl)2CuCl((di-sec-butyl)phen)]}(1), 2-sec-butyl-1,10-phenanthrolinedichlorocopper(II) {([mono-sec-butyl)phen) CuCl2} (2), 2,9-di-n-butyl-1,10-phenanthrolinedichlorocopper(II) {[(di-n-butyl)phen) CuCl2}(3), 2-n-butyl-1,10-phenanthrolinedichlorocopper(II) {[(mono-n-butyl)phen) CuCl2} (4), 2,9-di-methyl-1,10-phenanthrolineaquadichlorocopper(II) {[(di-methyl)phen) Cu(H2O)Cl2}(5), μ-dichloro-bis{6-sec-butyl-2,2'-bipyridinedichlorocopper(II)} {((mono-sec-butyl)bipy) ClCu(μ-Cl)2CuCl((mono-sec-butyl)bipy)} (6), 6,6'-di-methyl-2,2'-bipyridinedichlorocopper(II) {(6,6'-di-methyl)bipy) CuCl2} (7), and 4,4'-dimethyl-2,2'-bipyridinedichlorocopper(II) {(4,4'-di-methyl)bipy) CuCl2} (8). These complexes have been characterized via elemental analysis, UV-vis spectroscopy, and mass spectrometry. Single crystal X-ray diffraction experiments revealed the complexes synthesized with the (di-sec-butyl)phen ligand (1) and (mono-sec-butyl)bipy ligand (6) crystallized as dimers in which two copper(II) centers are bridged by two chloride ligands. Conversely, complexes 2, 7, and 8 were isolated as monomeric species possessing distorted tetrahedral geometries, and the [((di-methyl)phen)Cu(H2O)Cl2] (5) complex was isolated as a distorted square pyramidal monomer possessing a coordinating aqua ligand. Compounds 1-8 were evaluated for their in vitro antitumor efficacy. Compounds 1, 5, and 7 in particular were found to exhibit remarkable activity against human derived lung cancer cells, yet this class of copper(II) compounds had minimal cytotoxic effect on non-cancerous cells. In vitro control experiments indicate the activity of the copper(II) complexes most likely does not arise from the

  6. Structural and magnetic effects of meso-substitution in alkyl-substituted metalloporphyrinate pi-cation radicals: characterization of [Fe(TalkylP*)(Cl)]SbCl6 (alkyl = ethyl and n-propyl).

    PubMed

    Li, Ming; Neal, Teresa J; Wyllie, Graeme R A; Schulz, Charles E; Scheidt, W Robert

    2010-09-06

    We report the preparation and characterization of two meso-alkyl substituted porphyrin pi-cation radical derivatives, [Fe(TalkylP(*))(Cl)]SbCl(6) (alkyl = ethyl or propyl). Both complexes have been characterized by UV/vis/near-IR, IR, and Mossbauer spectroscopy, temperature-dependent solid-state magnetic susceptibility measurements, and X-ray structure determinations. All data for both oxidized species are consistent with the formulation of the complexes as ring-oxidized iron(III) porphyrin species. The molecular structures of the two five-coordinate species have the typical square-pyramidal coordination group of high-spin iron(III) derivatives. The crystal structures also reveal that the species form cofacial pi-pi dimers with lateral shifts of 1.44 A and 3.22 A, respectively, for the propyl and ethyl radical derivatives. Both radicals exhibit porphyrin cores with alternating bond distance patterns in the inner 16-membered ring. In addition, [Fe(TEtP(*))(Cl)]SbCl(6) and [Fe(TPrP(*))(Cl)]SbCl(6) have been characterized by temperature-dependent (6-300 K) magnetic susceptibility studies, the best fitting of the temperature-dependent moments reveal strong coupling between iron spins and porphyrin radical, and a smaller magnitude of antiferromagnetic coupling between ring radicals, which are opposite to those found in the five-coordinate iron(III) OEP radicals. The differences in structure and properties of the cation radical meso-alkyl and beta-alkyl derivatives possibly reflect differences in properties of a(1u)- and a(2u)-forming radicals.

  7. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  8. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  9. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  10. Communication: spectroscopic characterization of an alkyl substituted Criegee intermediate syn-CH(3)CHOO through pure rotational transitions.

    PubMed

    Nakajima, Masakazu; Endo, Yasuki

    2014-01-07

    An alkyl-substituted Criegee intermediate syn-CH3CHOO was detected in the gas phase through Fourier-transform microwave spectroscopy. Observed pure rotational transitions show a small splitting corresponding to the A∕E components due to the threefold methyl internal rotation. The rotational constants and the barrier height of the hindered methyl rotation were determined to be A = 17 586.5295(15) MHz, B = 7133.4799(41) MHz, C = 5229.1704(40) MHz, and V3 = 837.1(17) cm(-1). High-level ab initio calculations which reproduce the experimentally determined values well indicate that the in-plane C-H bond in the methyl moiety is trans to the C-O bond, and other two protons are directed to the terminal oxygen atom for the most stable structure of syn-CH3CHOO. The torsional barrier of the methyl top is fairly large in syn-CH3CHOO, implying a significant interaction between the terminal oxygen and the protons of the methyl moiety, which may be responsible for the high production yields of the OH radical from energized alkyl-substituted Criegee intermediates.

  11. Communication: Spectroscopic characterization of an alkyl substituted Criegee intermediate syn-CH{sub 3}CHOO through pure rotational transitions

    SciTech Connect

    Nakajima, Masakazu; Endo, Yasuki

    2014-01-07

    An alkyl-substituted Criegee intermediate syn-CH{sub 3}CHOO was detected in the gas phase through Fourier-transform microwave spectroscopy. Observed pure rotational transitions show a small splitting corresponding to the A/E components due to the threefold methyl internal rotation. The rotational constants and the barrier height of the hindered methyl rotation were determined to be A = 17 586.5295(15) MHz, B = 7133.4799(41) MHz, C = 5229.1704(40) MHz, and V{sub 3} = 837.1(17) cm{sup −1}. High-level ab initio calculations which reproduce the experimentally determined values well indicate that the in-plane C–H bond in the methyl moiety is trans to the C–O bond, and other two protons are directed to the terminal oxygen atom for the most stable structure of syn-CH{sub 3}CHOO. The torsional barrier of the methyl top is fairly large in syn-CH{sub 3}CHOO, implying a significant interaction between the terminal oxygen and the protons of the methyl moiety, which may be responsible for the high production yields of the OH radical from energized alkyl-substituted Criegee intermediates.

  12. Volatilization of benzene and eight alkyl-substituted benzene compounds from water

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1988-01-01

    Predicting the fate of organic compounds in streams and rivers often requires knowledge of the volatilization characteristics of the compounds. The reference-substance concept, involving laboratory-determined ratios of the liquid-film coefficients for volatilization of the organic compounds to the liquid-film coefficient for oxygen absorption, is used to predict liquid-film coefficients for streams and rivers. In the absence of experimental data, two procedures have been used for estimating these liquid-film coefficient ratios. These procedures, based on the molecular-diffusion coefficient and on the molecular weight, have been widely used but never extensively evaluated. Liquid-film coefficients for the volatilization of benzene and eight alkyl-substituted benzene compounds (toluene through n-octylbenzene) from water were measured in a constant-temperature, stirred water bath. Liquid-film coefficients for oxygen absorption were measured simultaneously. A range of water mixing conditions was used with a water temperature of 298.2 K. The ratios of the liquid-film coefficients for volatilization to the liquid-film coefficient for oxygen absorption for all of the organic compounds were independent of mixing conditions in the water. Experimental ratios ranged from 0.606 for benzene to 0.357 for n-octylbenzene. The molecular-diffusion-coefficient procedure accurately predicted the ratios for ethylbenzene through n-pentylbenzene with a power dependence of 0.566 on the molecular-diffusion coefficient, in agreement with published values. Predicted ratios for benzene and toluene were slightly larger than the experimental ratios. These differences were attributed to possible interactions between the molecules of these compounds and the water molecules and to benzene-benzene interactions that form dimers. Because these interactions also are likely to occur in natural waters, it was concluded that the experimental ratios are more correct than the predicted ratios for

  13. Enantioselective Friedel-Crafts alkylation for synthesis of 2-substituted indole derivatives.

    PubMed

    Zhang, Yulong; Liu, Xiaohua; Zhao, Xiaohu; Zhang, Jianlin; Zhou, Lin; Lin, Lili; Feng, Xiaoming

    2013-12-14

    An efficient catalytic asymmetric intermolecular C2 Friedel-Crafts alkylation reaction between N-methyl skatole and β,γ-unsaturated α-ketoesters has been realized by a chiral N,N'-dioxide-Ni(II) complex. The corresponding indole derivatives were obtained in good yield (up to 96%) with excellent enantioselectivities (up to 99% ee) under mild reaction conditions.

  14. Chromatographic techniques for the determination of alkyl-phenols, tocopherols and other minor polar compounds in raw and roasted cold pressed cashew nut oils.

    PubMed

    Gómez-Caravaca, Ana María; Verardo, Vito; Caboni, Maria Fiorenza

    2010-11-19

    Anacardium occidentale belongs to the family Anacardiaceae and is principally grown in tropical America (Mexico, Peru, Brazil, etc.) and India. Cashew nuts contain low amounts of hydroxy alkyl phenols that come from an oily liquid present in their shell and that is known as cashew-nut shell liquid. This paper reports the alkyl phenols composition of cold pressed raw and roasted cashew nut oil. First of all, cashew nut shell liquid was used for a basic fractionation of the alkyl phenol classes by preparative TLC and definitively identified by GC-MS and GC-FID. Anacardic acids were the major alkylphenols contained in both oils followed by cardol, cardanol and 2-methylcardol compounds, respectively. Raw and roasted oils did not show different compositions except for cardanols. The oil produced from roasted cashew nut reported a higher concentration of cardanols. Furthermore, tocopherols and other minor polar compounds were determined by HPLC-FLD and HPLC-DAD-MS, respectively. Tocopherol content varied in a range of 171.48-29.56mg/100g from raw to roasted cashew nut oil, being β-tocopherol the one which presented a higher decrease (93.68%). Also minor polar compounds in cashew oil decreased after roasting from 346.52 to 262.83mg/kg.

  15. [Determination of alkyl-phenols in textiles by in-tube capillary solid-phase extraction-gas chromatography].

    PubMed

    Zhang, Luohong; Du, Ting; Zhong, Jiayu

    2015-10-01

    An in-tube capillary solid-phase extraction (SPE) -gas chromatography (GC) method was developed for confirmation and quantitative determination of octylphenol (OP) and nonylphenol (NP) in textiles. To make the in-tube capillary SPE column, the best SPE cartridge was chosen from four kinds of SPE cartridges. The adsorbent in the cartridge was used as the filling material to make the in-tube capillary SPE column. The nature, volume used, flow rate and adsorption capacity of the eluent were compared. Finally, the in-tube capillary solid-phase extraction was combined with gas chromatography to detect the alkyl phenols (APs). Abselut NEXUS extraction cartridge was chosen as the best solid phase extractant. The optimal in-tube capillary SPE extraction conditions were as follows: 1.2 μL methanol and 1.2 μL ultra-pure water for activating the extraction column, 1.2 μL methanol for eluting, 0.4 μL/min for solution loading. The method showed a good linear relationship in the low concentration range, and the enrichment ratios for the APs were about 100 times. The detection limits of octylphenol and nonylphenol were 3.7 μg/L and 4.5 μg/L, respectively. The recoveries of octylphenol were 85.6%-98.2%, and those of nonylphenol were 83.8%-95.7%. The experimental results demonstrated that the method is simple, rapid, and useful for detecting APs in textiles.

  16. Stereoselective formation of quaternary stereogenic centers via alkylation of α-substituted malonate-imidazolidinones.

    PubMed

    Bixa, Thobela; Hunter, Roger; Andrijevic, Ana; Petersen, Wade; Su, Hong; Dhoro, Francis

    2015-01-16

    A new stereoselective alkylation methodology is presented for formation of chiral, nonracemic quaternary centers via a chiral auxiliary protocol involving α-alkylated malonate imidazolidinones. Based on two X-ray structures of quaternized products, the diastereoselectivity observed may be rationalized via a transition-state involving an s-transC-N conformation of the C-N bond of the auxiliary, with the metal cation (K(+)) chelated into the malonate six-membered hole as a Z-enolate. A deprotection protocol involving ethanethiolate exchange of the imide to the corresponding thioester, followed by a standard Fukuyama reduction and a borohydride reduction, furnishes α,α'-quaternized β-hydroxypropionates in high ee overall.

  17. Exploring the potential of high resolution mass spectrometry for the investigation of lignin-derived phenol substitutes in phenolic resin syntheses.

    PubMed

    Dier, Tobias K F; Fleckenstein, Marco; Militz, Holger; Volmer, Dietrich A

    2017-03-23

    Chemical degradation is an efficient method to obtain bio-oils and other compounds from lignin. Lignin bio-oils are potential substitutes for the phenol component of phenol formaldehyde (PF) resins. Here, we developed an analytical method based on high resolution mass spectrometry that provided structural information for the synthesized lignin-derived resins and supported the prediction of their properties. Different model resins based on typical lignin degradation products were analyzed by electrospray ionization in negative ionization mode. Utilizing enhanced mass defect filter techniques provided detailed structural information of the lignin-based model resins and readily complemented the analytical data from differential scanning calorimetry and thermogravimetric analysis. Relative reactivity and chemical diversity of the phenol substitutes were significant determinants of the outcome of the PF resin synthesis and thus controlled the areas of application of the resulting polymers. Graphical abstract ᅟ.

  18. Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

    SciTech Connect

    Jiang, Tingshun Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

    2014-10-15

    Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH{sub 3}-TPD and N{sub 2} physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)–MCM-48 samples, SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO{sub 4}{sup 2−}/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h{sup −1} and the reaction temperature is 140 °C. - Highlights: • Sulfuric acid functional mesoporous solid acid catalysts were prepared via impregnation method. • The alkylation of phenol with tert-butyl alcohol was carried out over these solid acid catalysts. • The catalytic activity of SO{sub 4}{sup 2−}/Zr-MCM-48-25 catalyst is much higher than that of the others. • A maximum phenol conversion of 91.6% was achieved under optimum reaction conditions for SO{sub 4}{sup 2−}/Zr-MCM-48-25.

  19. Modelling and simulation of photocatalytic oxidation mechanism of chlorohalogenated substituted phenols in batch systems: Langmuir-Hinshelwood approach.

    PubMed

    Khuzwayo, Z; Chirwa, E M N

    2015-12-30

    This study investigated, modelled and simulated the influence of multi-chlorohalogenation in heterogeneous photocatalytic degradation of substituted phenols (pentachlorophenol (PCP), trichlorophenol (TCP), dichlorophenol (DCP), and monochlorophenol (CP)). The Langmuir-Hinshelwood approach was applied to determine oxidation kinetics. Aquasim 2.0 computational software was used to model, simulate and estimate model parameters of the different chlorophenols. Chemical adsorption equilibrium isotherms for the four chlorophenols and phenol were studied and modelled for adsorption onto titanium dioxide (TiO2) semiconductor catalyst. Langmuir adsorption parameters were determined and used to calculate adsorption constant and maximum adsorption capacity. The adsorption of chloride phenolics onto titanium dioxide catalyst increased in the order of 4 - CP < DCP < Ph < TCP < PCP. Photocatalytic studies analysed the efficiency of oxidation and found improved degradation with higher chloride substituted phenolics in the order of PCP > TCP > DCP ≥ 4 - CP. Photocatalytic parameters were calculated and estimated along with sensitivity and uncertainty analyses.

  20. Detoxification of alkyl methylphosphonofluoridates by an oxime-substituted β-cyclodextrin--an in vitro structure-activity study.

    PubMed

    Bierwisch, Anne; Zengerle, Michael; Thiermann, Horst; Kubik, Stefan; Worek, Franz

    2014-01-13

    Detoxification rates of a series of alkyl methylphosphonofluoridates by an oxime-substituted β-cyclodextrin (β-CD) were assessed quantitatively by using an AChE inhibition assay. The cyclodextrin (CD) derivative was identified in previous work as a highly active cyclosarin scavenger. Here, a structure-activity relationship was established by investigating the effect of this CD on the detoxification of sarin derivatives differing in the structure of the alkoxy residue. The results show that detoxification rates correlate with the steric bulk and chain length of the alkoxy group in the organophosphonate (OP). OPs with larger, more bulky residues are detoxified more rapidly, with the exception of soman, which is bearing a pinacolyloxy side chain. In addition, the substituted CD was in every case more active than unsubstituted, native β-CD with up to a 400-fold difference. Comparing the kinetic results obtained with the known thermodynamic stabilities of related β-CD complexes indicate that detoxification rates generally increase when the alkoxy residue on the OP is exchanged by a residue, which forms a more stable complex with β-CD. This correlation lends support to the proposed mode of action of the substituted CD, involving initial complexation of the OP followed by reaction between the CD and the OP. The moderate to high efficacy on the detoxification of sarin derivatives suggests the potential applicability of this CD as a small molecule scavenger for G-type nerve agents.

  1. Synthesis, characterization, and in vitro SAR evaluation of N,N'-bis(arylmethyl)-C(2)-alkyl substituted imidazolium salts.

    PubMed

    DeBord, Michael A; Wagers, Patrick O; Crabtree, Steven R; Tessier, Claire A; Panzner, Matthew J; Youngs, Wiley J

    2017-01-15

    A series of C(2)-alkyl substituted N,N'-bis(arylmethyl)imidazolium salts were synthesized, characterized, and tested for their in vitro anti-cancer activity against multiple non-small cell lung cancer cell lines by our group and the National Cancer Institute's-60 human tumor cell line screen to establish a structure-activity relationship. Compounds are related to previously published N,N'-bis(arylmethyl)imidazolium salts but utilize the historical quinoline motif and anion effects to increase the aqueous solubility. Multiple derivatives displayed high anti-cancer activity with IC50 values in the nanomolar to low micromolar range against a panel of non-small cell lung cancer cell lines. Several of these derivatives have high aqueous solubilities with potent anti-proliferative properties and are ideal candidates for future in vivo xenograft studies and have high potential to progress into clinic use.

  2. Hydrogen-atom transfer reactions from ortho-alkoxy-substituted phenols: an experimental approach.

    PubMed

    Amorati, Riccardo; Menichetti, Stefano; Mileo, Elisabetta; Pedulli, Gian Franco; Viglianisi, Caterina

    2009-01-01

    The role of intramolecular hydrogen bonding (HB) on the bond-dissociation enthalpy (BDE) of the phenolic O-H and on the kinetics of H-atom transfer to peroxyl radicals (k(inh)) of several 2-alkoxyphenols was experimentally quantified by the EPR equilibration technique and by inhibited autoxidation studies. These compounds can be regarded as useful models for studying the H-atom abstraction from 2-OR phenols, such as many lignans, reduced coenzyme Q and curcumin. The effects of the various substituents on the BDE(O-H) of 2-methoxy, 2-methoxy-4-methyl, 2,4-dimethoxyphenols versus phenol were measured in benzene solution as -1.8; -3.7; -5.4 kcal mol(-1), respectively. In the case of polymethoxyphenols, significant deviations from the BDE(O-H) values predicted by the additive effects of the substituents were found. The logarithms of the k(inh) constants in cumene were inversely related to the BDE(O-H) values, obeying a linear Evans-Polanyi plot with the same slope of other substituted phenols and a y-axis intercept slightly smaller than that of 2,6-dimethyl phenols. In the cases of phenols having the 2-OR substituent included in a five-membered condensed ring (i.e, compounds 9-11), both conformational isomers in which the OH group points toward or away from the oxygen in position 2 were detected by FTIR spectroscopy and the intramolecular HB strength was thus estimated. The contribution to the BDE(O-H) of the ortho-OR substituent in 9, corrected for intramolecular HB formation, was calculated as -5.6 kcal mol(-1). The similar behaviour of cyclic and non-cyclic ortho-alkoxy derivatives clearly showed that the preferred conformation of the OMe group in ortho-methoxyphenoxyl radicals is that in which the methyl group points away from the phenoxyl oxygen, in contrast to the geometries predicted by DFT calculations.

  3. C5'-Alkyl Substitution Effects on Digitoxigenin α-l-Glycoside Cancer Cytotoxicity.

    PubMed

    Wang, Hua-Yu Leo; Qi, Zhang; Wu, Bulan; Kang, Sang-Woo; Rojanasakul, Yon; O'Doherty, George A

    2011-04-14

    A highly regio- and stereo-selective asymmetric synthesis of various C5'-alkyl side chains of rhamnosyl- and amicetosyl-digitoxigenin analogs has been established via palladium-catalyzed glycosylation with post-glycosylated dihydroxylation or diimide reduction. The C5'-methyl group in both α-l-rhamnose and α-l-amicetose digitoxin analogs displayed a steric directed apoptosis induction and tumor growth inhibition against non-small cell human lung cancer cells (NCI-H460). The anti-tumor activity is significantly reduced when the steric hindrance is increased at C5'-stereocenter.

  4. Chiral phosphoric acid catalyzed highly enantioselective Friedel-Crafts alkylation reaction of C3-substituted indoles to β,γ-unsaturated α-ketimino esters.

    PubMed

    Bi, Bo; Lou, Qin-Xin; Ding, Yu-Yang; Chen, Sheng-Wei; Zhang, Sha-Sha; Hu, Wen-Hui; Zhao, Jun-Ling

    2015-02-06

    A highly enantioselective C2 Friedel-Crafts alkylation reaction of 3-substituted indoles to β,γ-unsaturated α-ketimino esters has been developed. This reaction was efficiently catalyzed by a chiral phosphoric acid catalyst. The corresponding C2-substituted indole derivatives, bearing an α-ketimino ester motif, were obtained in moderate to high yields (up to 93%) and with high enantioselectivities (up to >99% ee).

  5. Supramolecular assembly and nanostructures of a series of luminol derivatives with aromatic/alkyl substituted groups in Langmuir-Blodgett films.

    PubMed

    Jiao, Tifeng; Xing, Yuanyuan; Zhang, Qingrui; Zhang, Li; Liu, Minghua; Zhou, Jingxin; Gao, Faming

    2014-06-01

    A series of functional luminol derivatives with aromatic and alkyl substituted groups has been designed and synthesized from the reaction of the corresponding chloride precursors with luminol. These compounds can be spread on water surface to form stable Langmuir films at the air-water interface. It has been found that UV and IR spectra confirmed the characteristic aromatic segment, imide group, and aromatic/alkyl substituted groups. In addition, for the interfacial assembly process of compounds with alkyl substituted groups, there are obvious spectral changes for the alkyl chains. AFM results indicated that various different aggregated domains may be fabricated in the transferred LB films. For all cases, the substituted groups in molecular structures have an important effect in regulating the aggregation mode and spectral changes in organized molecular films. The present results showed that the modified luminol derivatives may have potential application in functional material fields such as ECL sensor, which may give some insight to study the relationship between the molecular structures and supramolecular aggregation of amphiphiles in organized molecular films.

  6. Hydroxylation of p-substituted phenols by tyrosinase: Further insight into the mechanism of tyrosinase activity

    SciTech Connect

    Munoz-Munoz, Jose Luis; Berna, Jose; Garcia-Molina, Maria del Mar; Garcia-Molina, Francisco; Garcia-Ruiz, Pedro Antonio; Varon, Ramon [Departamento de Quimica-Fisica, Escuela de Ingenieros Industriales de Albacete, Universidad de Castilla la Mancha, Avda. Espana s and others

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer The action the copper complexes and tyrosinase on phenols is equivalent. Black-Right-Pointing-Pointer Isotope effect showed that nucleophilic attack to copper atom may be the slower step. Black-Right-Pointing-Pointer The value of {rho} (Hammett constant) supports an electrophilic aromatic substitution. Black-Right-Pointing-Pointer Data obtained in steady state pH 7 conditions support the mechanism of Scheme 1SM. -- Abstract: A study of the monophenolase activity of tyrosinase by measuring the steady state rate with a group of p-substituted monophenols provides the following kinetic information: k{sub cat}{sup m} and the Michaelis constant, K{sub M}{sup m}. Analysis of these data taking into account chemical shifts of the carbon atom supporting the hydroxyl group ({delta}) and {sigma}{sub p}{sup +}, enables a mechanism to be proposed for the transformation of monophenols into o-diphenols, in which the first step is a nucleophilic attack on the copper atom on the form E{sub ox} (attack of the oxygen of the hydroxyl group of C-1 on the copper atom) followed by an electrophilic attack (attack of the hydroperoxide group on the ortho position with respect to the hydroxyl group of the benzene ring, electrophilic aromatic substitution with a reaction constant {rho} of -1.75). These steps show the same dependency on the electronic effect of the substituent groups in C-4. Furthermore, a study of a solvent deuterium isotope effect on the oxidation of monophenols by tyrosinase points to an appreciable isotopic effect. In a proton inventory study with a series of p-substituted phenols, the representation of k{sub cat}{sup f{sub n}}/k{sub cat}{sup f{sub 0}} against n (atom fractions of deuterium), where k{sub cat}{sup f{sub n}} is the catalytic constant for a molar fraction of deuterium (n) and k{sub cat}{sup f{sub 0}} is the corresponding kinetic parameter in a water solution, was linear for all substrates. These results indicate that

  7. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  8. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  9. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  10. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  11. 40 CFR 721.7785 - Substituted alkyl aminomethylene polyphosphonic acid, salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyphosphonic acid, salt (generic). 721.7785 Section 721.7785 Protection of Environment ENVIRONMENTAL PROTECTION... acid, salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted alkylamino methylene polyphosphonic acid,...

  12. Evaluation of the antioxidant properties of propofol and its nitrosoderivative. comparison with homologue substituted phenols.

    PubMed

    Rigobello, Maria Pia; Stevanato, Roberto; Momo, Federico; Fabris, Sabrina; Scutari, Guido; Boscolo, Rita; Folda, Alessandra; Bindoli, Alberto

    2004-03-01

    Propofol (2,6-diisopropylphenol), some substituted phenols (2,6-dimethylphenol and 2,6-ditertbutylphenol) and their 4-nitrosoderivatives have been compared for their scavenging ability towards 1,1-diphenyl-2-picrylhydrazyl and for their inhibitory action on lipid peroxidation. These products were also compared to the classical antioxidants butylated hydroxytoluene and butylated hydroxyanisole. When measuring the reactivity of the various phenolic derivatives with 1,1-diphenyl-2-picrylhydrazyl the following order of effectiveness was observed: butylated hydroxyanisole > propofol > 2,6-dimethylphenol > 2,6-di-tertbutylphenol > butylated hydroxytoluene. In cumene hydroperoxide-dependent microsomal lipid peroxidation, propofol acts as the most effective antioxidant, while butylated hydroxyanisole, 2,6-di-tertbutylphenol and butylated hydroxytoluene exhibit a rather similar effect, although lower than propofol. In the iron/ascorbate-dependent lipid peroxidation propofol, at concentrations higher than 10 microM, exhibits antioxidant properties comparable to those of butylated hydroxytoluene and butylated hydroxyanisole, 2,6-Dimethylphenol is scarcely effective in both lipoperoxidative systems. The antioxidant properties of the various molecules depend on their hydrophobic characteristics and on the steric and electronic effects of their substituents. However, the introduction of the nitroso group in the 4-position almost completely removes the antioxidant properties of the examined compounds. The nitrosation of the aromatic ring of antioxidant molecules and the consequent loss of antioxidant capacity can be considered a condition potentially occurring in vivo since nitric oxide and its derivatives are continuously formed in biological systems.

  13. Pd(II)-Catalyzed Alkylation of Tertiary Carbon via Directing-Group-Mediated C(sp(3))-H Activation: Synthesis of Chiral 1,1,2-Trialkyl Substituted Cyclopropanes.

    PubMed

    Hoshiya, Naoyuki; Takenaka, Kei; Shuto, Satoshi; Uenishi, Jun'ichi

    2016-01-04

    A Pd(OAc)2-catalyzed alkylation reaction of the tertiary carbon of chiral cyclopropane substrates with alkyl iodides and bromides via C(sp(3))-H activation has been developed. This is an elusive example of a C-H activation-mediated alkylation of tertiary carbon to effectively construct a quaternary carbon center. The alkylation proceeded with various alkyl halides, including those of functional groups, to provide a variety of chiral cis- and trans-1,1,2,-trialkyl substituted cyclopropanes of medicinal chemical importance.

  14. Synthesis and highly potent hypolipidemic activity of alpha-asarone- and fibrate-based 2-acyl and 2-alkyl phenols as HMG-CoA reductase inhibitors.

    PubMed

    Mendieta, Aarón; Jiménez, Fabiola; Garduño-Siciliano, Leticia; Mojica-Villegas, Angélica; Rosales-Acosta, Blanca; Villa-Tanaca, Lourdes; Chamorro-Cevallos, Germán; Medina-Franco, José L; Meurice, Nathalie; Gutiérrez, Rsuini U; Montiel, Luisa E; Cruz, María Del Carmen; Tamariz, Joaquín

    2014-11-01

    In the search for new potential hypolipidemic agents, the present study focused on the synthesis of 2-acyl phenols (6a-c and 7a-c) and their saturated side-chain alkyl phenols (4a-c and 5a-c), and on the evaluation of their hypolipidemic activity using a murine Tyloxapol-induced hyperlipidemic protocol. The whole series of compounds 4-7 greatly and significantly reduced elevated serum levels of total cholesterol, LDL-cholesterol, and triglycerides, with series 6 and 7 showing the greatest potency ever found in our laboratory. At the minimum dose (25mg/kg/day), the latter compounds lowered cholesterol by 68-81%, LDL by 72-86%, and triglycerides by 59-80%. This represents a comparable performance than that shown by simvastatin. Experimental evidence and docking studies suggest that the activity of these derivatives is associated with the inhibition of HMG-CoA reductase.

  15. Modified carbon pseudopotential for use in ONIOM calculations of alkyl-substituted metallocenes.

    PubMed

    Lewin, John L; Cramer, Christopher J

    2008-12-18

    Nonrelativistic carbon 1s core pseudopotentials are optimized for substituted cyclopentadienide ring carbons for use in integrated molecular orbital molecular orbital (IMOMO) and integrated molecular orbital molecular mechanics (IMOMM) calculations where the Cp ring substituents are not included in the high-level IMOMO or IMOMM subsystem. Use of the optimized pseudopotential within the IMOMO framework leads to significant improvements in predicted carbonyl stretching frequencies for a series of Cp-ring-methylated zirconocenes compared to using a standard carbon pseudopotential. The technology is less successful in the IMOMM implementation.

  16. Phenols

    NASA Astrophysics Data System (ADS)

    Weber, Manfred; Weber, Markus

    Up to the end of the nineteenth century, phenol was recovered primarily from coal tar. With the commercialization of the phenolic resins, the demand for phenol grew significantly. Currently, the cumene-to-phenol process is the predominant synthetic route for the production of phenol. It is accompanied by acetone as a co-product. Cumene is oxidized with oxygen to form cumene hydroperoxide. The peroxide is subsequently decomposed to phenol and acetone, using a strong mineral acid as catalyst. The products are purified in a series of distillation columns. The cumene-to-phenol process is described in more detail in this chapter. An overview is given about synthetic routes via direct oxidation of benzene. None of these alternative routes has been commercialized. The chapter also gives an overview of global supply and use of phenol in 2008. Finally, the main natural sources and synthetic routes for cresols, xylenols, resorcinol, and bisphenol-A are described. These components are used as comonomers for special phenolic resins.

  17. Polarization Effects for Hydrogen-Bonded Complexes of Substituted Phenols with Water and Chloride Ion.

    PubMed

    Jorgensen, William L; Jensen, Kasper P; Alexandrova, Anastassia N

    2007-11-01

    Variations in hydrogen-bond strengths are investigated for complexes of nine para-substituted phenols (XPhOH) with a water molecule and chloride ion. Results from ab initio HF/6-311+G(d, p) and MP2/6-311+G(d, p)//HF/6-311+G(d, p) calculations are compared with those from the OPLS-AA and OPLS/CM1A force fields. In the OPLS-AA model, the partial charges on the hydroxyl group of phenol are not affected by the choice of para substituent, while the use of CM1A charges in the OPLS/CM1A approach does provide charge redistribution. The ab initio calculations reveal a 2.0-kcal/mol range in hydrogen-bond strengths for the XPhOH⋯OH(2) complexes in the order X = NO(2) > CN > CF(3) > Cl > F > H >OH >CH(3) > NH(2). The pattern is not well-reproduced with OPLS-AA, which also compresses the variation to 0.7 kcal/mol. However, the OPLS/CM1A results are in good accord with the ab initio findings for both the ordering and range, 2.3 kcal/mol. The hydrogen bonding is, of course, weaker with XPhOH as acceptor, the order for X is largely inverted, and the range is reduced to ca. 1.0 kcal/mol. The substituent effects are found to be much greater for the chloride ion complexes with a range of 11 kcal/mol. For quantitative treatment of such strong ion-molecule interactions the need for fully polarizable force fields is demonstrated.

  18. The influence of substituted phenols on the sol:gel transition of hydroxypropyl methylcellulose (HPMC) aqueous solutions.

    PubMed

    Banks, Simon R; Pygall, Samuel R; Bajwa, Gurjit S; Doughty, Stephen W; Timmins, Peter; Melia, Colin D

    2014-01-30

    The influence of the physicochemical parameters of substituted aromatic molecules on the phase transition from sol to gel of hydroxypropyl methylcellulose (HPMC) has been investigated using a homologous series of substituted phenols. Using a turbimetric methodology, concentration dependent suppression of phase transition temperature of HPMC was observed for phenol and its derivatives, including methyl-, nitro- and chloro-substituted molecules. Although no strong direct relationship between single molecular physicochemical properties of the phenolic compounds (such as pKa, LogP and other molecular descriptors) and ΔCPT was found for the compounds tested, a successful prediction of behaviour could be obtained by using a combination of parameters. This suggested that the interaction mechanism between HPMC and the substituted aromatic moiety is a complex summation of the different molecular physicochemical properties. Identification of these potentially deleterious chemical moieties may be of value in a pharmaceutical context when considering preformulation of drug structures containing them. An incompatibility between drug and polymer may be indicative of deleterious effects resulting from formulation with hydrophilic matrix dosage forms containing cellulose ethers such as HPMC.

  19. Reaction of bromine and chlorine with phenolic compounds and natural organic matter extracts--Electrophilic aromatic substitution and oxidation.

    PubMed

    Criquet, Justine; Rodriguez, Eva M; Allard, Sebastien; Wellauer, Sven; Salhi, Elisabeth; Joll, Cynthia A; von Gunten, Urs

    2015-11-15

    Phenolic compounds are known structural moieties of natural organic matter (NOM), and their reactivity is a key parameter for understanding the reactivity of NOM and the disinfection by-product formation during oxidative water treatment. In this study, species-specific and/or apparent second order rate constants and mechanisms for the reactions of bromine and chlorine have been determined for various phenolic compounds (phenol, resorcinol, catechol, hydroquinone, phloroglucinol, bisphenol A, p-hydroxybenzoic acid, gallic acid, hesperetin and tannic acid) and flavone. The reactivity of bromine with phenolic compounds is very high, with apparent second order rate constants at pH 7 in the range of 10(4) to 10(7) M(-1) s(-1). The highest value was recorded for the reaction between HOBr and the fully deprotonated resorcinol (k = 2.1 × 10(9) M(-1) s(-1)). The reactivity of phenolic compounds is enhanced by the activating character of the phenolic substituents, e.g. further hydroxyl groups. With the data set from this study, the ratio between the species-specific rate constants for the reactions of chlorine versus bromine with phenolic compounds was confirmed to be about 3000. Phenolic compounds react with bromine or chlorine either by oxidation (electron transfer, ET) or electrophilic aromatic substitution (EAS) processes. The dominant process mainly depends on the relative position of the hydroxyl substituents and the possibility of quinone formation. While phenol, p-hydroxybenzoic acid and bisphenol A undergo EAS, hydroquinone, catechol, gallic acid and tannic acid, with hydroxyl substituents in ortho or para positions, react with bromine by ET leading to quantitative formation of the corresponding quinones. Some compounds (e.g. phloroglucinol) show both partial oxidation and partial electrophilic aromatic substitution and the ratio observed for the pathways depends on the pH. For the reaction of six NOM extracts with bromine, electrophilic aromatic substitution

  20. Tandem Esterification/1,4-Addition-Type Friedel-Crafts Alkylation Reactions of Phenols/Naphthols with Olefinic Thioazlactones: Access to Functionalized 1,2-Dihydrobenzo[f]chromen-3-ones and 3,4-Dihydrochromen-2-ones.

    PubMed

    Ziyaei Halimehjani, Azim; Khoshdoun, Maryam

    2016-07-01

    An efficient approach for the synthesis of novel alkyl 2,3-dihydro-3-oxo-1-aryl-1H-benzo[f]chromen-2-ylcarbamodithioates and alkyl 3,4-dihydro-2-oxo-4-aryl-2H-chromen-3-ylcarbamodithioates from 2-(alkylthio)thioazlactones (thioazlactones) and phenols or naphthols catalyzed by PTSA was developed. The reaction proceeds via a domino esterification/intramolecular 1,4-addition-type Friedel-Crafts alkylation reaction to afford interesting complex molecules by a simple procedure with high yields and diastereoselectivity. An X-ray analysis was carried out to firmly establish the stereochemistry of the products.

  1. Direct, one-pot reductive alkylation of anilines with functionalized acetals mediated by triethylsilane and TFA. Straightforward route for unsymmetrically substituted ethylenediamine.

    PubMed

    Righi, Marika; Bedini, Annalida; Piersanti, Giovanni; Romagnoli, Federica; Spadoni, Gilberto

    2011-01-21

    A new, robust, and reliable method has been developed for the selective reductive N-alkylation of primary and secondary aromatic amines with some functionalized acetals using TFA/Et(3)SiH as a reagent combination. A variety of unsymmetrically substituted ethylenediamines can be synthesized in a one-pot procedure in excellent yields at room temperature. This new procedure offers significant advantages over previous synthetic approaches, including brevity, mild reaction conditions, excellent yields, and high functional group tolerance.

  2. Prediction and determination of the stereochemistry of the 1,3,5-trimethyl-substituted alkyl chain in verucopeptin, a microbial metabolite.

    PubMed

    Yoshimura, Aya; Kishimoto, Shinji; Nishimura, Shinichi; Otsuka, Saori; Sakai, Yuki; Hattori, Akira; Kakeya, Hideaki

    2014-08-01

    For the prediction of the relative stereochemistry of 1,3-dimethyl substitution in alkyl chains, a simple approach based on (1)H NMR data was recently proposed; Δδ values of methylene protons located between methyl-substituted methine carbons can be diagnostic for predicting it. Here we applied this empirical "geminal proton rule" to verucopeptin, a lipopeptide from Streptomyces sp. To determine the absolute stereochemistry of the 1,3,5-trimethyl-substituted alkyl chain in verucopeptin, we converted the corresponding alkyl chain to a carboxylic acid by oxidative cleavage. The geminal proton rule clearly predicted the relative stereochemistry as 31S*,33S*,35R*. This prediction was definitely confirmed by synthesizing four possible diastereomers and comparing their NMR spectra. Furthermore, we reinvestigated the geminal proton rule using reported compounds and our synthesized compounds. Our result strongly suggests that the rule was solid, at least for predicting the stereochemistry of 2,4-dimethylated and 2,4,6-trimethylated fatty acids.

  3. A 4-alkyl-substituted analogue of guaiacol shows greater repellency to savannah tsetse (Glossina spp.).

    PubMed

    Saini, Rajindar K; Hassanali, Ahmed

    2007-05-01

    The responses of Glossina morsitans morsitans Westwood to guaiacol (2-methoxyphenol), a mild repellent constituent of bovid odors, and seven analogues comprising 2-methoxyfuran, 2,4-dimethylphenol, 2-methoxy-4-methylphenol (4-methylguaiacol), 4-ethyl-2-methoxyphenol (4-ethylguaiacol), 4-allyl-2-methoxyphenol (4-allylguaiacol; eugenol), 3,4-methylenedioxytoluene, and 3,4-dimethoxystyrene were compared in a two-choice wind tunnel. The 4-methyl-substituted derivative (2-methoxy-4-methylphenol) was found to elicit stronger repellent responses from the flies compared with guaiacol. None of the other analogues showed significant repellent effects on flies. 4-Methylguaiacol, guaiacol, and eugenol (which was included because of previous reports of its repellency against a number of arthropods) were further evaluated in the field with wild populations of predominantly Glossina pallidipes Austen. The presence of guaiacol or eugenol near odor-baited traps caused some nonsignificant reduction in the number of tsetse catches at relatively high release rates (approximately 50 mg/hr). In contrast, the 4-methyl derivative at three different release rates (2.2, 4.5, and 9.0 mg/hr) reduced trap catches of baited traps in a dose-response manner. At 10 mg/hr release rate, it reduced the catches of baited and unbaited traps by approximately 80 and approximately 70%, respectively. In addition, the compound not only reduced the number of tsetse attracted to natural ox odor (approximately 80%), but also had an effect on their feeding responses, reducing the proportion that fed on an ox by more than 80%. Our study shows that the presence of a methyl substituent at the 4-position of guaiacol enhances the repellency of the molecule to savannah tsetse and suggests that 4-methylguaiacol may represent a promising additional tool in the arsenal of techniques in trypanosomiasis control.

  4. Reactivity of Cations and Zwitterions Formed in Photochemical and Acid-Catalyzed Reactions from m-Hydroxycycloalkyl-Substituted Phenol Derivatives.

    PubMed

    Cindro, Nikola; Antol, Ivana; Mlinarić-Majerski, Kata; Halasz, Ivan; Wan, Peter; Basarić, Nikola

    2015-12-18

    Three m-substituted phenol derivatives, each with a labile benzylic alcohol group and bearing either protoadamantyl 4, homoadamantyl 5, or a cyclohexyl group 6, were synthesized and their thermal acid-catalyzed and photochemical solvolytic reactivity studied, using preparative irradiations, fluorescence measurements, nanosecond laser flash photolysis, and quantum chemical calculations. The choice of m-hydroxy-substitution was driven by the potential for these phenolic systems to generate m-quinone methides on photolysis, which could ultimately drive the excited-state pathway, as opposed to forming simple benzylic carbocations in the corresponding thermal route. Indeed, thermal acid-catalyzed reactions gave the corresponding cations, which undergo rearrangement and elimination from 4, only elimination from 5, and substitution and elimination from 6. On the other hand, upon photoexcitation of 4-6 to S1 in a polar protic solvent, proton dissociation from the phenol, coupled with elimination of the benzylic OH (as hydroxide ion) gave zwitterions (formal m-quinone methides). The zwitterions exhibit reactivity different from the corresponding cations due to a difference in charge distribution, as shown by DFT calculations. Thus, protoadamantyl zwitterion has a less nonclassical character than the corresponding cation, so it does not undergo 1,2-shift of the carbon atom, as observed in the acid-catalyzed reaction.

  5. N-Alkyl-Substituted Isatins Enhance P2X7 Receptor-Induced Interleukin-1β Release from Murine Macrophages.

    PubMed

    Sluyter, Ronald; Vine, Kara L

    2016-01-01

    Extracellular adenosine 5'-triphosphate (ATP) activates the P2X7 receptor channel to induce the rapid release of the proinflammatory cytokine, interleukin- (IL-) 1β, from macrophages. Microtubule rearrangements are thought to be involved in this process. Some isatin derivatives alter microtubules and display anticancer activities. The current study investigated the effect of isatin and seven structurally diverse isatin derivatives on P2X7-mediated IL-1β release from murine J774 macrophages. ATP-induced IL-1β and lactate dehydrogenase (LDH) release were assessed by specific colorimetric assays. P2X7 activity was determined by flow cytometric measurements of ATP-induced cation dye uptake. Cytotoxicity of isatin derivatives was determined using a tetrazolium-based colorimetric assay. ATP caused rapid IL-1β release in a concentration-dependent manner, and this process was completely impaired by the P2X7 antagonist, AZ10606120. In contrast, 5,7-dibromo-N-(p-methoxybenzyl)isatin (NAI) and 3-{4-[5,7-dibromo-1-(4-methoxybenzyl)-2-oxoindolin-3-ylidenamino]phenyl}propanoic acid (NAI-imine) enhanced P2X7-induced IL-1β release by twofold compared to that of isatin and the parent molecule, 5,7-dibromoisatin. NAI and NAI-imine had minimal effect on P2X7-induced dye uptake and LDH release. In contrast, 24-hour incubation with NAI and NAI-imine (in the absence of exogenous ATP) induced macrophage death in a concentration-dependent manner. In conclusion, this study demonstrates that N-alkyl-substituted isatins enhance P2X7 receptor-induced IL-1β release from murine macrophages. Thus, in addition to direct anticancer effects, these compounds may also impact inflammatory and immune cells within the tumor microenvironment.

  6. Phenol

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 02 / 006 TOXICOLOGICAL REVIEW OF Phenol ( CAS No . 108 - 95 - 2 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2002 U.S . Environmental Protection Agency Washington D.C . DISCLAIMER Mention of trade names or commercial products does n

  7. Synthesis of novel 1,2,3-triazole substituted-N-alkyl/aryl nitrone derivatives, their anti-inflammatory and anticancer activity.

    PubMed

    Sambasiva Rao, P; Kurumurthy, C; Veeraswamy, B; Santhosh Kumar, G; Poornachandra, Y; Ganesh Kumar, C; Vasamsetti, Sathish Babu; Kotamraju, Srigiridhar; Narsaiah, B

    2014-06-10

    A series of novel 1,2,3-triazole substituted N-phenyl nitrone derivatives 5a-e were prepared in three steps starting from 1-substituted-1,2,3-triazole-4-carbaldehydes 2 via Schiff's base formation, reduction followed by oxidation. Similarly, 1,2,3-triazole substituted N-alkyl nitrone derivatives 6a-p were prepared in single step starting from compound 2 on reaction with N-alkyl hydroxylamine hydrochlorides. All the final compounds were screened for anti-inflammatory and anticancer activity against various cancer cell lines. Among the compounds tested, the compounds 5a, 5d, 6a, 6b, 6m and 6o exhibited significant inhibition of IL-1β secretion as a measure of anti-inflammatory activity. Compound 5b, 5c, 6h, 6i and 6o exhibited significant activity against all the cell lines (A549, COLO 205, MDA-MB 231 and PC-3) at IC50 values of <15 μM.

  8. Biodegradation of the endocrine disrupter 4-tert-octylphenol by the yeast strain Candida rugopelliculosa RRKY5 via phenolic ring hydroxylation and alkyl chain oxidation pathways.

    PubMed

    Rajendran, Ranjith Kumar; Huang, Shir-Ly; Lin, Chu-Ching; Kirschner, Roland

    2017-02-01

    4-(1,1,3,3-tetramethylbutane)-phenol (4-tert-OP) is one of the most prevalent endocrine disrupting pollutants. Information about bioremediation of 4-tert-OP remains limited, and no study has been reported on the mechanism of 4-tert-OP degradation by yeasts. The yeast Candida rugopelliculosa RRKY5 was proved to be able to utilize 4-methylphenol, bisphenol A, 4-ethylphenol, 4-tert-butylphenol, 4-tert-OP, 4-tert-nonylphenol, isooctane, and phenol under aerobic conditions. The optimum conditions for 4-tert-OP degradation were 30°C, pH 5.0, and an initial 4-tert-OP concentration of 30mgL(-1); the maximum biodegradation rate constant was 0.107d(-1), equivalent to a minimum half-life of 9.6d. Scanning electron microscopy revealed formation of arthroconidia when cells were grown in the presence of 4-tert-OP, whereas the cells remained in the budding form without 4-tert-OP. Identification of the 4-tert-OP degradation metabolites using liquid chromatography-hybrid mass spectrometry revealed three different mechanisms via both branched alkyl side chain and aromatic ring cleavage pathways.

  9. Oxidation and mineralisation of substituted phenols by Fenton's reagent and catalytic wet oxidation.

    PubMed

    Santos, A; Rodriguez, S; Garcia-Ochoa, F; Yustos, P

    2007-01-01

    Catalytic abatement of solutions of 1,000 mg/L in phenol, ortho and para nitrophenol and ortho and para cresols was acomplished by using two catalytic systems. Fenton's reagent was used at 50 degrees C by adding 10 mg/L of ferrous cation and different dosages of H2O2. The mixture was reacting isothermically in a batch way during 3 hours. Catalytic wet oxidation (CWO) was carried out by using a commercial Activated Carbon, Industrial React FE01606A, CWO runs were carried out in a fixed bed reactor (FBR) with concurrent upflow. Temperature and oxygen pressure of the reactor were set to 160 degrees C and 16 bar, respectively. While phenols are quicky oxidised by the Fenton reagent higher mineralisation was obtained in the CWO process.

  10. Oxidation of substituted phenols using copper(II) metallatriangles formed through ligand sharing.

    PubMed

    Mahiya, Kuldeep; Kumar, Ravinder; Lloret, Francisco; Mathur, Pavan

    2014-12-10

    Reaction of N(2),N(2')-bis-[(1-butyl-benzimidazol-2yl)methyl]biphenyl-2,2'-dicarboxamide (L) with CuX2⋅nH2O in methanol leads to the assembly of four trinuclear Cu(II) complexes with the general formula [Cu3(L)3X3]⋅3X⋅nH2O⋅mMeCN, where X=Cl(-), Br(-), NO3(-) and C6H5COO(-) and n=0-5, m=0-8 (compounds 1-4, respectively). The structure of one of the complex contains three Cu(II) metal ions at the corners of an equilateral triangle. Each of the copper(II) are coordinated through two benzimidazolyl imine N-atoms and two amide carbonyl O-atoms and the apical position is occupied by an anionic nitrate ion, leading to a distorted square pyramidal environment. The magnetic susceptibility data were analyzed through Hamiltonian H=-J (S1S2+S2S3+S1S3) obtaining -J=0.16, 0.12, 0.15 and 0.14cm(-1) for 1-4, respectively. X-Band EPR spectra typically show a broad single line at 120K with g∼2.11. Oxidation of phenols was studied homogeneously using copper(II) metallatriangles (1-3) as catalyst in acetonitrile. The oxidation of 2,4,6-tri-tert-butyl phenol yields the corresponding quinone after oxidative dealkylation. The oxidation of 2-amino-5-methyl phenol yields the corresponding phenoxazinone while the oxidation of 2-amino-4-tert-butyl phenol yields the phenoxazine instead of phenoxazinone. The products so obtained were analyzed by NMR and X-ray single crystallography.

  11. Use of bark-derived pyrolysis oils ass a phenol substitute in structural panel adhesives

    SciTech Connect

    Louisiana Pacific Corp

    2004-03-01

    The main objective of this program was to pilot the world's first commercial-scale production of an acceptable phenol formaldehyde (PF) resin containing natural resin (NR) ingredients, for use as an adhesive in Oriented-Strand Board (OSB) and plywood panel products. Natural Resin products, specifically MNRP are not lignin ''fillers''. They are chemically active, natural phenolics that effectively displace significant amounts of phenol in PF resins, and which are extracted from bark-derived and wood-derived bio-oils. Other objectives included the enhancement of the economics of NR (MNRP) production by optimizing the production of certain Rapid Thermal Processing (RTP{trademark}) byproducts, particularly char and activated carbon. The options were to activate the char for use in waste-water and/or stack gas purification. The preliminary results indicate that RTP{trademark} carbon may ultimately serve as a feedstock for activated carbon synthesis, as a fuel to be used within the wood product mill, or a fuel for an electrical power generating facility. Incorporation of the char as an industrial heat source for use in mill operations was L-P's initial intention for the carbon, and was also of interest to Weyerhaeuser as they stepped into in the project.

  12. Highly enantioselective synthesis of beta-heteroaryl-substituted dihydrochalcones through Friedel-Crafts alkylation of indoles and pyrrole.

    PubMed

    Wang, Wentao; Liu, Xiaohua; Cao, Weidi; Wang, Jun; Lin, Lili; Feng, Xiaoming

    2010-02-01

    A highly enantioselective Friedel-Crafts (F-C) alkylation of indoles and pyrrole with chalcone derivatives catalyzed by a chiral N,N'-dioxide-Sc(OTf)(3) complex has been developed that tolerates a wide range of substrates. The reaction proceeds in moderate to excellent yields and high enantioselectivities (85-92 % enantiomeric excess) using 2 mol % (for indole) or 0.5 mol % (for pyrrole) catalyst loading, which showed the potential value of the catalyst system. Meanwhile, a strong positive nonlinear effect was observed. On the basis of the experimental results and previous reports, a possible working model is proposed to explain the origin of the activation and asymmetric induction.

  13. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  14. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  15. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  16. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  17. 40 CFR 721.1580 - Disubstituted benzene ether, polymer with substituted phenol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Disubstituted benzene ether, polymer... Significant New Uses for Specific Chemical Substances § 721.1580 Disubstituted benzene ether, polymer with... chemical substance generically identified as disubstituted benzene ether, polymer with substituted...

  18. Toxicity and biodegradability of selected N-substituted phenols under anaerobic conditions

    SciTech Connect

    Donlon, B.; Razo-Flores, E.; Hwu, C.S.; Field, J.; Lettinga, G.

    1995-12-31

    The anaerobic toxicity and biodegradability of N-substituted aromatics were evaluated in order to obtain information on their ultimate biotreatment. The toxicity of selected N-substituted aromatic compounds toward acetoclastic methanogens in granular sludge was measured in batch assays. This toxicity was highly correlated with compound hydrophobicity, indicating that partitioning into the bacterial membranes was an important factor in the toxicity. However, other factors, such as chemical interactions with key cell components, were suggested to be playing an important role. Nitroaromatic compounds were, on the average, over 300-fold more toxic than their amino-substituted counterparts. This finding suggests that the facile reduction of nitro-groups known to occur in anaerobic environments would result in a high level of detoxification. To test this hypothesis, continuous lab-scale upward-flow anaerobic sludge bed reactors treating 2-nitrophenol and 4-nitrophenol were established. The 4-nitrophenol was readily converted to the corresponding 4-aminophenol, whereas complete mineralization of 2-nitrophenol via intermediate formation of 2-aminophenol was obtained. These conversions led to a dramatic detoxification of the nitrophenols, because it was feasible to treat the highly toxic nitrophenolics at high organic loading rates.

  19. Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: ππ*-πσ* energy gap propensity and ortho-substitution effect.

    PubMed

    Pino, G A; Oldani, A N; Marceca, E; Fujii, M; Ishiuchi, S-I; Miyazaki, M; Broquier, M; Dedonder, C; Jouvet, C

    2010-09-28

    Lifetimes of the first electronic excited state (S(1)) of fluorine and methyl (o-, m-, and p-) substituted phenols and their complexes with one ammonia molecule have been measured for the 0(0) transition and for the intermolecular stretching σ(1) levels in complexes using picosecond pump-probe spectroscopy. Excitation energies to the S(1) (ππ*) and S(2) (πσ*) states are obtained by quantum chemical calculations at the MP2 and CC2 level using the aug-cc-pVDZ basis set for the ground-state and the S(1) optimized geometries. The observed lifetimes and the energy gaps between the ππ* and πσ* states show a good correlation, the lifetime being shorter for a smaller energy gap. This propensity suggests that the major dynamics in the excited state concerns an excited state hydrogen detachment or transfer (ESHD/T) promoted directly by a S(1)/S(2) conical intersection, rather than via internal conversion to the ground-state. A specific shortening of lifetime is found in the o-fluorophenol-ammonia complex and explained in terms of the vibronic coupling between the ππ* and πσ* states occurring through the out-of-plane distortion of the C-F bond.

  20. Studies on enhancing operational stability of a reusable laccase-based biosensor probe for detection of ortho-substituted phenolic derivatives.

    PubMed

    Sarika, C; Rekha, K; Narasimha Murthy, B

    2015-12-01

    An amperometric principle-based biosensor containing immobilized enzyme laccase from Trametes versicolor was developed for detection of ortho-substituted phenolic derivatives. Different immobilization methods for Trametes versicolor laccase enzyme on cellophane membrane and the enhancement of operational stability of the immobilized enzyme electrode using various protein-based stabilizing agents were studied. Among tested methods of immobilization, co-cross-linking method with bovine serum albumin was superior to the other methods in terms of sensitivity, limit of detection, response time, and operating and thermal stability. Biosensor response reached steady state within 3 min and exhibited maximum activity at 45 °C and pH 6.8. The sensitivity of the ortho-substituted phenols for the test biosensor developed with co-cross-linking method of immobilization using bovine serum albumin as the protein-based stabilizing agent was in the order: 2-aminophenol > guaiacol(2-methoxyphenol) > catechol(2-hydroxyphenol) > cresol(2-methyl phenol) > 2-chlorophenol. Validation of the newly developed biosensor by comparison with HPLC showed good agreement in the results. A newly developed biosensor was applied for quantification of ortho-substituted phenols in simulated effluent samples.

  1. Effects of odd-even side chain length of alkyl-substituted diphenylbithiophenes on first monolayer thin film packing structure.

    PubMed

    Akkerman, Hylke B; Mannsfeld, Stefan C B; Kaushik, Ananth P; Verploegen, Eric; Burnier, Luc; Zoombelt, Arjan P; Saathoff, Jonathan D; Hong, Sanghyun; Atahan-Evrenk, Sule; Liu, Xueliang; Aspuru-Guzik, Alán; Toney, Michael F; Clancy, Paulette; Bao, Zhenan

    2013-07-31

    Because of their preferential two-dimensional layer-by-layer growth in thin films, 5,5'bis(4-alkylphenyl)-2,2'-bithiophenes (P2TPs) are model compounds for studying the effects of systematic chemical structure variations on thin-film structure and morphology, which in turn, impact the charge transport in organic field-effect transistors. For the first time, we observed, by grazing incidence X-ray diffraction (GIXD), a strong change in molecular tilt angle in a monolayer of P2TP, depending on whether the alkyl chain on the P2TP molecules was of odd or even length. The monolayers were deposited on densely packed ultrasmooth self-assembled alkane silane modified SiO2 surfaces. Our work shows that a subtle change in molecular structure can have a significant impact on the molecular packing structure in thin film, which in turn, will have a strong impact on charge transport of organic semiconductors. This was verified by quantum-chemical calculations that predict a corresponding odd-even effect in the strength of the intermolecular electronic coupling.

  2. Novel polycarbo-substituted alkyl (thieno[3,2-c]quinoline)-2-carboxylates: synthesis and cytotoxicity studies.

    PubMed

    Mphahlele, Malose Jack; Maluleka, Marole Maria; Makhafola, Tshepiso Jan; Mabeta, Peace

    2014-11-13

    Direct one-pot base-promoted conjugate addition-elimination of 6,8-dibromo-4-chloroquinoline-3-carbaldehyde with methyl mercaptoacetate and subsequent cyclization afforded methyl [(6,8-dibromothieno[3,2-c]quinoline)]-2-carboxylate. The latter undergoes Suzuki-Miyaura cross-coupling with arylboronic acids to yield exclusively the corresponding alkyl [(6,8-diarylthieno[3,2-c]quinoline)]-2-carboxylates,. The cytotoxicity of the prepared compounds was evaluated against the human breast cancer cell line MCF-7 using the MTT assay. The effects of compounds 2, 3c and 4d on cell kinetics were further determined using the xCELLigence Real Time Cell Analysis (RTCA) system. In both the MTT assay and Real Time Cell Analysis, the compounds inhibited cancer cell growth in a dose- and time-dependent manner. Furthermore, on the basis of the calculated LC50 values, the compounds compared favourably with nocodazole, a well-established anticancer drug.

  3. Investigating the activity of 2-substituted alkyl-6-(2,5-dioxopyrrolidin-1-yl)hexanoates as skin penetration enhancers.

    PubMed

    Brychtova, Katerina; Opatrilova, Radka; Raich, Ivan; Kalinowski, Danuta S; Dvorakova, Lenka; Placek, Lukas; Csollei, Jozef; Richardson, Des R; Jampilek, Josef

    2010-12-15

    Skin penetration enhancers are used in the formulation of transdermal delivery systems for drugs that are otherwise not sufficiently skin-permeable. We generated two series of esters by multi-step synthesis with substituted 6-aminohexanoic acid as potential transdermal penetration enhancers by multi-step synthesis. The synthesis of all newly prepared compounds is presented here. Structure confirmation of all generated compounds was accomplished by (1)H NMR, (13)C NMR, IR and MS spectroscopy. All the prepared compounds were analyzed using RP-HPLC and their lipophilicity (logk) was determined. The hydrophobicity (logP/ClogP) of the studied compounds was also calculated using two commercially available programs and 3D structures of the selected compounds were investigated by means of ab initio calculations of geometry and molecular dynamic simulations. All the synthesized esters were tested for their in vitro transdermal penetration-enhancing activity and showed higher enhancement ratios than oleic acid. The highest enhancement ratios were exhibited by compound 5f (C((2)) substituted with piperidine-2-one, C(11) ester chain) and 5a (C((2)) substituted with piperidine-2-one, C(6) ester chain). The series with a ω-lactam ring (piperidin-2-one; 5a-g), showed slightly higher activities than those with morpholine (6a-6g). All of the agents showed minimal anti-proliferative activity (IC(50) >6.25μM), indicating they would have low cytotoxicity when administered as chemical penetration enhancers. The relationships between the lipophilicity and the chemical structure of the studied compounds, as well as the correlation between their chemical structure and transdermal penetration-enhancing activity, are discussed.

  4. Stilbazulenyl nitrone (STAZN): a nitronyl-substituted hydrocarbon with the potency of classical phenolic chain-breaking antioxidants.

    PubMed

    Becker, David A; Ley, James J; Echegoyen, Luis; Alvarado, Robert

    2002-05-01

    Stilbazulenyl nitrone (STAZN), 8, a nitronyl-substituted hydrocarbon, is a novel second-generation azulenyl nitrone with significantly enhanced potency as a chain-breaking antioxidant vs conventional alpha-phenyl nitrones previously investigated as antioxidant therapeutics. A convenient (1)H NMR-based assay for assessing the potency of chain-breaking antioxidants has shown that STAZN is ca. 300 times more potent in inhibiting the free radical-mediated aerobic peroxidation of cumene than is PBN and the experimental stroke drug NXY-059. Such levels of antioxidant efficacy are unprecedented among archetypal alpha-phenyl nitrone spin traps. Furthermore, STAZN outperforms such classical phenolic antioxidants as BHT and probucol and rivals the antioxidant potency of Vitamin E in a polar medium comprised of 80% cumene and 20% methanol. The Volodarskii electron-transfer mechanism involving the intermediacy of the STAZN radical cation has been implicated in attempts to ascertain the basis for the increased potency of STAZN over the three alpha-phenyl nitrones PBN, S-PBN, and NXY-059.

  5. Synthesis, characterization, in vitro SAR and in vivo evaluation of N,N'bisnaphthylmethyl 2-alkyl substituted imidazolium salts against NSCLC.

    PubMed

    DeBord, Michael A; Southerland, Marie R; Wagers, Patrick O; Tiemann, Kristin M; Robishaw, Nikki K; Whiddon, Kyle T; Konopka, Michael C; Tessier, Claire A; Shriver, Leah P; Paruchuri, Sailaja; Hunstad, David A; Panzner, Matthew J; Youngs, Wiley J

    2017-02-15

    Alkyl- and N,N'-bisnaphthyl-substituted imidazolium salts were tested in vitro for their anti-cancer activity against four non-small cell lung cancer cell lines (NCI-H460, NCI-H1975, HCC827, A549). All compounds had potent anticancer activity with 2 having IC50 values in the nanomolar range for three of the four cell lines, a 17-fold increase in activity against NCI-H1975 cells when compared to cisplatin. Compounds 1-4 also showed high anti-cancer activity against nine NSCLC cell lines in the NCI-60 human tumor cell line screen. In vitro studies performed using the Annexin V and JC-1 assays suggested that NCI-H460 cells treated with 2 undergo an apoptotic cell death pathway and that mitochondria could be the cellular target of 2 with the mechanism of action possibly related to a disruption of the mitochondrial membrane potential. The water solubilities of 1-4 was over 4.4mg/mL using 2-hydroxypropyl-β-cyclodextrin as a chemical excipient, thereby providing sufficient solubility for systemic administration.

  6. A Single-Component Conductor Based on a Radical Gold Dithiolene Complex with Alkyl-Substituted Thiophene-2,3-dithiolate Ligand.

    PubMed

    Higashino, Toshiki; Jeannin, Olivier; Kawamoto, Tadashi; Lorcy, Dominique; Mori, Takehiko; Fourmigué, Marc

    2015-10-19

    Alkyl-substituted thiophene-2,3-dithiolate ligands are prepared through a Thio-Claisen rearrangement of 4,5-bis(propargylthio)-1,3-dithiole-2-thione derivatives. The two novel dithiolate ligands, namely, 4,5-dimethyl-thiophene-2,3-dithiolate (α-Me2tpdt) and 4-ethyl-5-methyl-thiophene-2,3-dithiolate (α-EtMetpdt), are engaged in anionic Au(III) square planar complexes formulated as [Au(α-Me2tpdt)2](-) and [Au(α-EtMetpdt)2](-), isolated as Ph4P(+) salts. Monoelectronic oxidation gives the neutral radical complexes [Au(α-Me2tpdt)2](•) and [Au(α-EtMetpdt)2](•). The latter crystallizes into uniform stacks with limited interstack interactions, giving rise to a calculated half-filled band structure. It exhibits a semiconducting behavior with room temperature conductivity of 3 × 10(-3) S cm(-1), indicating that this single-component conductor can be described as a Mott insulator. The different structures observed in [Au(α-EtMetpdt)2](•) and the known [Au(Et-thiazdt)2](•) complex (Et-thiazdt: N-ethyl-thiazoline-2-thione-4,5-dithiolate), despite their very similar shapes, are tentatively attributed to differences in the electronic structures of the ligand skeleton.

  7. 4-Alkyl-3,5-difluorophenyl-Substituted Benzodithiophene-Based Wide Band Gap Polymers for High-Efficiency Polymer Solar Cells.

    PubMed

    Li, Guangwu; Gong, Xue; Zhang, Jicheng; Liu, Yahui; Feng, Shiyu; Li, Cuihong; Bo, Zhishan

    2016-02-17

    Two novel polymers PTFBDT-BZS and PTFBDT-BZO with 4-alkyl-3,5-difluorophenyl substituted benzodithiophene as the donor unit, benzothiadiazole or benzooxadiazole as the acceptor unit, and thiophene as the spacer have been synthesized and used as donor materials for polymer solar cells (PSCs). These two polymers exhibited wide optical band gaps of about 1.8 eV. PSCs with the blend of PTFBDT-BZS:PC71BM (1:2, by weight) as the active layer fabricated without using any processing additive and any postannealing treatment showed power conversion efficiency (PCE) of 8.24% with an open circuit voltage (Voc) of 0.89 V, a short circuit current (Jsc) of 12.67 mA/cm(2), and a fill factor (FF) of 0.73 under AM 1.5G illumination, indicating that PTFBDT-BZS is a very promising donor polymer for PSCs. The blend of PTFBDT-BZO:PC71BM showed a lower PCE of 5.67% with a Voc of 0.96 V, a Jsc of 9.24 mA/cm(2), and an FF of 0.64. One reason for the lower PCE is probably due to that PTFBDT-BZO has a smaller LUMO offset with PC71BM, which cannot provide enough driving force for charge separation. And another reason is probably due to that PTFBDT-BZO has a lower hole mobility in comparison with PTFBDT-BZS.

  8. Resonance raman and absorption studies of the configurations of photochromic 3-alkyl-substituted 1,5-diphenylformazans: steric effect of the substituent

    NASA Astrophysics Data System (ADS)

    Hiura, Hidefumi; Takahashi, Hiroaki

    1989-09-01

    Resonance Raman spectra reveal that 3-alkyl-substituted 1,5-diphenylformazans exist as one of the following three isomeric species in the solid state: the yellow isomer has the trans- anti-s- trans configuration with respect to the NN, CN and CN bonds of the formazan skeleton, the red isomer has the trans- syn-s- trans configuration and the other red isomer has the trans- syn-s- cis configuration. The relative stabilities of these isomers are determined by the bulkiness of the substituent. When the substituent is small, the fully extended trans- anti-s- trans configuration is most stable. However, when the substituent is large, the partially folded trans- syn-s- trans configuration becomes stable and when the substituent is very bulky, the more folded trans- syn-s cis configuration is most stable. In solution these isomers are in equilibrium, the relative abundance being dependent on the nature of the solvent as well as on the bulkiness of the substituent.

  9. Radioiodination of Aryl-Alkyl Cyclic Sulfates

    PubMed Central

    Mushti, Chandra; Papisov, Mikhail I.

    2015-01-01

    Among the currently available positron emitters suitable for Positron Emission Tomography (PET), 124I has the longest physical half-life (4.2 days). The long half-life and well-investigated behavior of iodine in vivo makes 124I very attractive for pharmacological studies. In this communication, we describe a simple yet effective method for the synthesis of novel 124I labeled compounds intended for PET imaging of arylsulfatase activity in vivo. Arylsulfatases have important biological functions, and genetic deficiencies of such functions require pharmacological replacement, the efficacy of which must be properly and non-invasively evaluated. These enzymes, even though their natural substrates are mostly of aliphatic nature, hydrolyze phenolic sulfates to phenol and sulfuric acid. The availability of [124I]iodinated substrates is expected to provide a PET-based method for measuring their activity in vivo. The currently available methods of synthesis of iodinated arylsulfates usually require either introducing of a protected sulfate ester early in the synthesis or introduction of sulfate group at the end of synthesis in a separate step. The described method gives the desired product in one step from an aryl-alkyl cyclic sulfate. When treated with iodide, the source cyclic sulfate opens with substitution of iodide at the alkyl center and gives the desired arylsulfate monoester. PMID:23135631

  10. Development and application of a simultaneous SPE-method for polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, heterocyclic PAHs (NSO-HET) and phenols in aqueous samples from German Rivers and the North Sea.

    PubMed

    Siemers, Anne-Kathrin; Mänz, Jan Sebastian; Palm, Wolf-Ulrich; Ruck, Wolfgang K L

    2015-03-01

    Polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs (NSO-HETs), alkylated PAHs and phenols are known as the prevailing contaminants in groundwater at tar contaminated sites. Besides these local sources, the concentrations and the distribution in particular of NSO-HETs in environmental samples, such as rivers, have received notably less attention. To investigate their occurrence in river basins two sensitive analytical methods for the simultaneous extraction of 86 substances including NSO-HETs, classical EPA-PAHs, alkylated PAHs and phenols were developed: liquid-liquid extraction for the whole water phase and solid phase extraction for the dissolved water phase only. Solely GC-MS or additionally LC-MSMS for fractionated basic nitrogen heterocycles (N-HETs) were used for quantification. Limits of quantification were in the low ngL(-1) range. Concentrations were determined in 29 aqueous samples from 8 relatively large rivers located in Lower Saxony (Germany) and the North Sea. NSO-HETs had comparable or even higher sum concentrations than EPA-PAHs. N-HETs, especially acridine and quinolines with concentrations of up to 20ngL(-1) per substance, were predominant.

  11. Influence of alkyl chain length on charge transport in symmetrically substituted poly(2,5-dialkoxy- p -phenylenevinylene) polymers

    NASA Astrophysics Data System (ADS)

    Tuladhar, Sachetan M.; Sims, Marc; Kirkpatrick, James; Maher, Robert C.; Chatten, Amanda J.; Bradley, Donal D. C.; Nelson, Jenny; Etchegoin, Pablo G.; Nielsen, Christian B.; Massiot, Philippe; George, Wayne N.; Steinke, Joachim H. G.

    2009-01-01

    We report on the hole transport characteristics, as measured by time of flight, of a family of symmetrically substituted dialkoxy poly( p -phenylenevinylene) polymers with different side-chain length. As side-chain length is decreased, the magnitude of the hole mobility μh increases while the field dependence of μh becomes more positive and the temperature dependence of μh becomes stronger. For the shortest side-chain derivative studied, μh exceeds 10-4cm2V-1s-1 at electric fields greater than 105Vcm-1 . The trend in magnitude of μh with side-chain length is consistent with the expected increase in electronic wave-function overlap as interchain separation decreases, while the trends in electric-field and temperature dependences of μh are consistent with increasing site energy disorder. We show that the electrostatic contribution to the site energy difference for pairs of oligomers follows the observed trend as a function of interchain separation, although the pairwise contribution is too small to explain the data quantitatively. Nonresonant Raman spectroscopy is used to characterize the microstructure of our films. We construct spatial maps of the Raman ratio I1280/I1581 and confirm an expected decrease in average film density with side-chain extension. The structural heterogeneity in the maps is analyzed but no clear correlation is observed with transport properties, suggesting that the structural variations relevant for charge transport occur on a length scale finer than the resolution of ˜1μm .

  12. Mechanistic insights into the oxidation of substituted phenols via hydrogen atom abstraction by a cupric-superoxo complex.

    PubMed

    Lee, Jung Yoon; Peterson, Ryan L; Ohkubo, Kei; Garcia-Bosch, Isaac; Himes, Richard A; Woertink, Julia; Moore, Cathy D; Solomon, Edward I; Fukuzumi, Shunichi; Karlin, Kenneth D

    2014-07-16

    To obtain mechanistic insights into the inherent reactivity patterns for copper(I)-O2 adducts, a new cupric-superoxo complex [(DMM-tmpa)Cu(II)(O2(•-))](+) (2) [DMM-tmpa = tris((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)amine] has been synthesized and studied in phenol oxidation-oxygenation reactions. Compound 2 is characterized by UV-vis, resonance Raman, and EPR spectroscopies. Its reactions with a series of para-substituted 2,6-di-tert-butylphenols (p-X-DTBPs) afford 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) in up to 50% yields. Significant deuterium kinetic isotope effects and a positive correlation of second-order rate constants (k2) compared to rate constants for p-X-DTBPs plus cumylperoxyl radical reactions indicate a mechanism that involves rate-limiting hydrogen atom transfer (HAT). A weak correlation of (k(B)T/e) ln k2 versus E(ox) of p-X-DTBP indicates that the HAT reactions proceed via a partial transfer of charge rather than a complete transfer of charge in the electron transfer/proton transfer pathway. Product analyses, (18)O-labeling experiments, and separate reactivity employing the 2,4,6-tri-tert-butylphenoxyl radical provide further mechanistic insights. After initial HAT, a second molar equiv of 2 couples to the phenoxyl radical initially formed, giving a Cu(II)-OO-(ArO') intermediate, which proceeds in the case of p-OR-DTBP substrates via a two-electron oxidation reaction involving hydrolysis steps which liberate H2O2 and the corresponding alcohol. By contrast, four-electron oxygenation (O-O cleavage) mainly occurs for p-R-DTBP which gives (18)O-labeled DTBQ and elimination of the R group.

  13. Mechanistic Insights into the Oxidation of Substituted Phenols via Hydrogen Atom Abstraction by a Cupric–Superoxo Complex

    PubMed Central

    2015-01-01

    To obtain mechanistic insights into the inherent reactivity patterns for copper(I)–O2 adducts, a new cupric–superoxo complex [(DMM-tmpa)CuII(O2•–)]+ (2) [DMM-tmpa = tris((4-methoxy-3,5-dimethylpyridin-2-yl)methyl)amine] has been synthesized and studied in phenol oxidation–oxygenation reactions. Compound 2 is characterized by UV–vis, resonance Raman, and EPR spectroscopies. Its reactions with a series of para-substituted 2,6-di-tert-butylphenols (p-X-DTBPs) afford 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) in up to 50% yields. Significant deuterium kinetic isotope effects and a positive correlation of second-order rate constants (k2) compared to rate constants for p-X-DTBPs plus cumylperoxyl radical reactions indicate a mechanism that involves rate-limiting hydrogen atom transfer (HAT). A weak correlation of (kBT/e) ln k2 versus Eox of p-X-DTBP indicates that the HAT reactions proceed via a partial transfer of charge rather than a complete transfer of charge in the electron transfer/proton transfer pathway. Product analyses, 18O-labeling experiments, and separate reactivity employing the 2,4,6-tri-tert-butylphenoxyl radical provide further mechanistic insights. After initial HAT, a second molar equiv of 2 couples to the phenoxyl radical initially formed, giving a CuII–OO–(ArO′) intermediate, which proceeds in the case of p-OR-DTBP substrates via a two-electron oxidation reaction involving hydrolysis steps which liberate H2O2 and the corresponding alcohol. By contrast, four-electron oxygenation (O–O cleavage) mainly occurs for p-R-DTBP which gives 18O-labeled DTBQ and elimination of the R group. PMID:24953129

  14. Multipotent MAO and cholinesterase inhibitors for the treatment of Alzheimer's disease: synthesis, pharmacological analysis and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amine.

    PubMed

    Samadi, Abdelouahid; de los Ríos, Cristóbal; Bolea, Irene; Chioua, Mourad; Iriepa, Isabel; Moraleda, Ignacio; Bartolini, Manuela; Andrisano, Vincenza; Gálvez, Enrique; Valderas, Carolina; Unzeta, Mercedes; Marco-Contelles, José

    2012-06-01

    The synthesis, pharmacological evaluation and molecular modeling of heterocyclic substituted alkyl and cycloalkyl propargyl amines 1-7 of type I, and 9-12 of type II, designed as multipotent inhibitors able to simultaneously inhibit monoamine oxidases (MAO-A/B) as well as cholinesterase (AChE/BuChE) enzymes, as potential drugs for the treatment of Alzheimer's disease, are described. Indole derivatives 1-7 of type I are well known MAO inhibitors whose capacity to inhibit AChE and BuChE was here investigated for the first time. As a result, compound 7 was identified as a MAO-B inhibitor (IC(50) = 31 ± 2 nM) and a moderately selective eqBuChE inhibitor (IC(50) = 4.7 ± 0.2 μM). Conversely, the new and readily available 5-amino-7-(prop-2-yn-1-yl)-6,7,8,9-tetrahydropyrido[2,3-b][1,6]naphthyridine derivatives 9-13 of type II are poor MAO inhibitors, but showed AChE selective inhibition, compound 12 being the most attractive as it acts as a non-competitive inhibitor on EeAChE (IC(50) = 25 ± 3 nM, K(i) = 65 nM). The ability of this compound to interact with the AChE peripheral binding site was confirmed by kinetic studies and by molecular modeling investigation. Studies on human ChEs confirmed that 12 is a selective AChE inhibitor with inhibitory potency in the submicromolar range. Moreover, in agreement with its mode of action, 12 was shown to be able to inhibit Aβ aggregation induced by hAChE by 30.6%.

  15. Inter-Ring Interactions in [Fe(TalkylP)(Cl)] (alkyl = ethyl, n-propyl, n-hexyl) Complexes: Control by meso-Substituted Groups.

    PubMed

    Li, Ming; Neal, Teresa J; Ehlinger, Noelle; Schulz, Charles E; Scheidt, W Robert

    2010-01-01

    Syntheses, molecular structures and magnetic susceptibilities of three meso-substituted high-spin iron(III) porphyrinate complexes ([Fe(TEtP)(Cl)], [Fe(TPrP)(Cl)], and [Fe(THexP)(Cl)]) are described. It was determined that the inter-ring interactions within each dimeric unit change upon alteration of the alkyl groups at the meso-positions. Magnetic exchange couplings between iron centers of the dimers are in accord with the trends in structural inter-ring geometries. Crystal data for [Fe(TEtP)(Cl)]: a = 10.1710(5) Å, b = 11.309(3) Å, c = 12.170(3) Å, α = 91.774(9) °, β = 113.170(14) °, γ = 112.149(9) °, V = 1165.2(4) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.0844 and ωR(2) = 0.2073 for observed data. Crystal data for [Fe([Fe(TPrP)(Cl)])(Cl)]: a = 13.040(2) Å, b = 15.221(2) Å, c = 14.6681(9) Å, β = 109.997(11) °, V = 2735.9(7) Å(3), monoclinic, P2(1)/n, Z = 4, R(1) = 0.0477 and ωR(2) = 0.1176 for observed data. Crystal data for [Fe(THexP)(Cl)]: a = 10.246(7) Å, b = 12.834(4) Å, c = 17.420(15) Å, α = 69.74(3) °, β = 87.52(4) °, γ, = 84.89(3) °, V = 2140(2) Å(3), triclinic, P1̄, Z = 2, R(1) = 0.1024 and ωR(2) = 0.2659 for observed data.

  16. Microwave-assisted combinatorial synthesis of hexa-substituted 1,4-dihydropyridines scaffolds using one-pot two-step multicomponent reaction followed by a S-alkylation.

    PubMed

    Li, Ming; Zuo, Zhengquan; Wen, Lirong; Wang, Shuwen

    2008-01-01

    A sequential one-pot two-step protocol for microwave-assisted synthesis of Hantzsch-type hexa-substituted 1,4-dihydropyridines has been developed. The three-component reactions of beta-aroylthioamides with aldehydes and acetonitrile derivatives produce the intermediates in situ followed by a S-alkylation to afford hexa-substituted 1,4-dihydropyridines. The reaction presumably proceeds via a Knoevenagel condensation-Michael addition-cyclocondensation-rearrangement-S N2 reaction sequence. Target compounds were obtained in high yields and simply purified by recrystallization. The novel method is complementary to the classical Hantzsch synthesis in that it is well-suited to the preparation of hexa-substituted 1,4-dihydropyridines.

  17. Degradation Pathway of Bisphenol A: Does ipso Substitution Apply to Phenols Containing a Quaternary α-Carbon Structure in the para Position?▿ †

    PubMed Central

    Kolvenbach, B.; Schlaich, N.; Raoui, Z.; Prell, J.; Zühlke, S.; Schäffer, A.; Guengerich, F. P.; Corvini, P. F. X.

    2007-01-01

    The degradation of bisphenol A and nonylphenol involves the unusual rearrangement of stable carbon-carbon bonds. Some nonylphenol isomers and bisphenol A possess a quaternary α-carbon atom as a common structural feature. The degradation of nonylphenol in Sphingomonas sp. strain TTNP3 occurs via a type II ipso substitution with the presence of a quaternary α-carbon as a prerequisite. We report here a new degradation pathway of bisphenol A. Consequent to the hydroxylation at position C-4, according to a type II ipso substitution mechanism, the C-C bond between the phenolic moiety and the isopropyl group of bisphenol A is broken. Besides the formation of hydroquinone and 4-(2-hydroxypropan-2-yl)phenol as the main metabolites, further compounds resulting from molecular rearrangements consistent with a carbocationic intermediate were identified. Assays with resting cells or cell extracts of Sphingomonas sp. strain TTNP3 under an 18O2 atmosphere were performed. One atom of 18O2 was present in hydroquinone, resulting from the monooxygenation of bisphenol A and nonylphenol. The monooxygenase activity was dependent on both NADPH and flavin adenine dinucleotide. Various cytochrome P450 inhibitors had identical inhibition effects on the conversion of both xenobiotics. Using a mutant of Sphingomonas sp. strain TTNP3, which is defective for growth on nonylphenol, we demonstrated that the reaction is catalyzed by the same enzymatic system. In conclusion, the degradation of bisphenol A and nonylphenol is initiated by the same monooxygenase, which may also lead to ipso substitution in other xenobiotics containing phenol with a quaternary α-carbon. PMID:17557840

  18. Chiral N,N'-Dioxide-Scandium(III) Complex-Catalyzed Asymmetric Friedel-Crafts Alkylation Reaction of ortho-Hydroxybenzyl Alcohols with C3-Substituted N-Protected Indoles.

    PubMed

    Zheng, Jianfeng; Lin, Lili; Dai, Li; Yuan, Xiao; Liu, Xiaohua; Feng, Xiaoming

    2016-12-12

    The first Lewis acid catalyzed asymmetric Friedel-Crafts alkylation reaction of ortho-hydroxybenzyl alcohols with C3-substituted indoles is described. A chiral N,N'-dioxide Sc(OTf)3 complex served not only to promote formation of ortho-quinone methides (o-QMs) in situ but also induced the asymmetry of the reaction. This methodology enables a novel activation of ortho-hydroxybenzyl alcohols, thus affording the desired chiral diarylindol-2-ylmethanes in up to 99 % yield and 99 % ee. A range of functional groups were also tolerated under the mild reaction conditions. Moreover, this strategy gives concise access to enantioenriched indole-fused benzoxocines.

  19. Regioselectivity of Birch reductive alkylation of biaryls.

    PubMed

    Lebeuf, Raphaël; Robert, Frédéric; Landais, Yannick

    2005-10-13

    [reaction: see text] The regioselectivity of the Birch reductive alkylation of polysubstituted biaryls has been investigated. Results indicate that regioselectivity is affected by the electronic nature of substituents on both aromatic rings. The electron-rich 3,5-dimethoxyphenyl moiety is selectively reduced and then alkylated, while phenols and aniline are not dearomatized under these conditions. Biaryls possessing a phenol moiety are alkylated on the second ring, providing that the acidic proton has been removed prior to the Li/NH3 reduction.

  20. A new iron(III) complex of glycine derivative of amine-chloro substituted phenol ligand: Synthesis, characterization and catechol dioxygenase activity

    NASA Astrophysics Data System (ADS)

    Saberikia, Iraj; Safaei, Elham; Kowsari, Mohammad Hossein; Lee, Yong-Ill; Cotic, Patricia; Bruno, Giuseppe; Rudbari, Hadi Amiri

    2012-12-01

    A new iron(III) complex of the glycine derivative of amine-chloro substituted phenol ligand (H3LGDC) has been prepared and characterized by IR, 1H NMR, UV-Vis spectroscopic techniques, cyclic voltammetry, ESI-MS and magnetic susceptibility studies. X-ray analysis reveals that in iron complex of FeLGDC the iron(III) center has a distorted trigonal bipyramidal coordination sphere and is surrounded by an amine nitrogen, a carboxylate, a water and two phenolate oxygen atoms. The DFT calculations with the UB3LYP/6-311++G** level optimized structure of the complex are in good agreement with experimental X-ray structural data. The variable-temperature magnetic susceptibility indicates that FeLGDC is the paramagnetic high spin iron(III) complex. It has been shown that electrochemical oxidation of this complex is ligand-centered due to the oxidation of phenolate to the phenoxyl radicals. This enzyme mimic utilized molecular oxygen in carrying out the oxidative cleavage of catechols with complete conversion at room temperature.

  1. Selective and Efficient Generation of ortho-Brominated para-Substituted Phenols in ACS-Grade Methanol.

    PubMed

    Georgiev, David; Saes, Bartholomeus W H; Johnston, Heather J; Boys, Sarah K; Healy, Alan; Hulme, Alison N

    2016-01-13

    The mono ortho-bromination of phenolic building blocks by NBS has been achieved in short reaction times (15-20 min) using ACS-grade methanol as a solvent. The reactions can be conducted on phenol, naphthol and biphenol substrates, giving yields of >86% on gram scale. Excellent selectivity for the desired mono ortho-brominated products is achieved in the presence of 10 mol % para-TsOH, and the reaction is shown to be tolerant of a range of substituents, including CH3, F, and NHBoc.

  2. Efficient and versatile catalysis of N-alkylation of heterocyclic amines with alcohols and one-pot synthesis of 2-aryl substituted benzazoles with newly designed ruthenium(II) complexes of PNS thiosemicarbazones.

    PubMed

    Ramachandran, Rangasamy; Prakash, Govindan; Selvamurugan, Sellappan; Viswanathamurthi, Periasamy; Malecki, Jan Grzegorz; Ramkumar, Venkatachalam

    2014-06-07

    Ruthenium(II) carbonyl complexes with phosphine-functionalized PNS type thiosemicarbazone ligands [RuCl(CO)(EPh3)(L)] (1-6) (E = P or As, L = 2-(2-(diphenylphosphino)benzylidene) thiosemicarbazone (PNS-H), 2-(2-(diphenylphosphino)benzylidene)-N-methylthiosemicarbazone (PNS-Me), 2-(2-(diphenylphosphino)benzylidene)-N-phenylthiosemicarbazone (PNS-Ph)) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, (1)H, (13)C, (31)P-NMR) as well as ESI mass spectrometry. The molecular structures of complexes 1, 2 and 6 were identified by means of single-crystal X-ray diffraction analysis. The analysis revealed that all the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate PNS fashion. All the ruthenium complexes (1-6) were tested as catalyst for N-alkylation of heteroaromatic amines with alcohols. Notably, complex 2 was found to be a very efficient and versatile catalyst towards N-alkylation of a wide range of heterocyclic amines with alcohols. Complex 2 can also catalyze the direct amination of 2-nitropyridine with benzyl alcohol to the corresponding secondary amine. Furthermore, a preliminary examination of performance for N,N-dialkylation of diamine showed promising results, giving good conversion and high selectivity. In addition, N-alkylation of ortho-substituted anilines (-NH2, -OH and -SH) led to the one-pot synthesis of 2-aryl substituted benzimidazoles, benzoxazoles and benzothiazoles, also revealing the catalytic activity of complex 2.

  3. A mild synthesis of new aryl vinyl ethers and diethyl 1-[(alkyl)(cyano)methyl]vinylphosphonates via the substitution of a 2,3-difunctional allyl bromide.

    PubMed

    Fray, Asma; Ben Kraïem, Jihène; Arfaoui, Aïcha; Amri, Hassen

    2014-01-01

    A novel class of aryl vinyl ethers 3 and diethyl 3-cyano-3-alkylprop-1-en-2-ylphosphonates 4 has been prepared, respectively, from coupling reaction of diethyl 1-(bromomethyl)-2-cyanovinylphosphonate 2 with phenols and Gilman reagents.

  4. Selective O-alkylation of phenol with methanol over sulphates supported on {gamma}-Al{sub 2}O{sub 3}

    SciTech Connect

    Samolada, M.C.; Grigoriadou, E.; Kiparissides, Z.; Vasalos, I.A.

    1995-03-01

    The reaction of phenol with methanol was studied in a fixed-bed reactor system as a potential source for the production of methyl aryl ethers. For this reason, the performance of alumina-supported catalysts impregnated with sulphate salts of metals of the groups VIIB and IIB was studied. The effects of reaction temperature, reaction time, type of metal, metal content, and potassium content on the selectivity of methyl aryl ethers (MAE), as well as the phenol conversion and the yield of MAE, were established. The reaction temperature and the potassium content were found mainly to affect the selectivity of the catalyst, the phenol conversion, and the yield of MAE. Empirical equations were drived which proved to be useful for predicting the performance of a catalyst over a broad range of reaction conditions. A catalyst (K{sub 3}{sup S}) containing only potassium (3 wt%) in the form of potassium sulphate supported on {gamma}-alumina was found to have the most promising performance compared to those reported in the literature in terms of MAE selectivity and phenol conversion at atmospheric pressure (selectivity of MAE = 98%, phenol conversion = 65 wt%). The catalyst remains stable over a broad range of temperatures (290-330{degrees}C). K{sub 3}{sup S} is an inexpensive catalyst, showing major selectivity advantages and product composition (anisole, 92 wt%; o-cresol, 8 wt%) and a low coke production (7 wt%). The presence of potassium sulphate in the catalyst proved to be the controlling factor for the production of MAE and it was found to be the active phase of the catalyst. The MAE selectivity of potassium sulphate catalysts in determined by the potassium content of the catalyst, while its optimum value is achieved, when acid sites of medium strength (+ 1.5 < H{sub 0} {le} + 4.8) with low acidity values 22 x 10{sup {minus}4} mmol/m{sup 2} exist on their surface. 35 refs., 6 figs., 6 tabs.

  5. Palladium-Catalyzed Arylation of Alkyl Sulfenate Anions.

    PubMed

    Jia, Tiezheng; Zhang, Mengnan; Jiang, Hui; Wang, Carol Y; Walsh, Patrick J

    2015-11-04

    A unique palladium-catalyzed arylation of alkyl sulfenate anions is introduced that affords aryl alkyl sulfoxides in high yields. Due to the base sensitivity of the starting sulfoxides, sulfenate anion intermediates, and alkyl aryl sulfoxide products, the use of a mild method to generate alkyl sulfenate anions was crucial to the success of this process. Thus, a fluoride triggered elimination strategy was employed with alkyl 2-(trimethylsilyl)ethyl sulfoxides to liberate the requisite alkyl sulfenate anion intermediates. In the presence of palladium catalysts with bulky monodentate phosphines (SPhos and Cy-CarPhos) and aryl bromides or chlorides, alkyl sulfenate anions were readily arylated. Moreover, the thermal fragmentation and the base promoted elimination of alkyl sulfoxides was overridden. The alkyl sulfenate anion arylation exhibited excellent chemoselectivity in the presence of functional groups, such as anilines and phenols, which are also known to undergo palladium catalyzed arylation reactions.

  6. Synthesis and characterization of a novel long-alkyl-chain ester-substituted benzimidazole gelator and its octan-1-ol solvate.

    PubMed

    Geiger, H Cristina; Zick, Patricia L; Roberts, William R; Geiger, David K

    2017-04-01

    The synthesis of a novel benzimidazole derivative with a long-chain-ester substituent, namely methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan-1-ol solvate, methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate octan-1-ol monosolvate, C22H26N2O3·C8H18O, (4), exhibits a four-molecule hydrogen-bonded motif in the solid state, with N-H...O hydrogen bonds between benzimidazole molecules and O-H...N hydrogen bonds between the octan-1-ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan-1-ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H...C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C-H...π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed.

  7. Predicting pK(a) values of substituted phenols from atomic charges: comparison of different quantum mechanical methods and charge distribution schemes.

    PubMed

    Svobodová Vareková, Radka; Geidl, Stanislav; Ionescu, Crina-Maria; Skrehota, Ondrej; Kudera, Michal; Sehnal, David; Bouchal, Tomás; Abagyan, Ruben; Huber, Heinrich J; Koca, Jaroslav

    2011-08-22

    The acid dissociation (ionization) constant pK(a) is one of the fundamental properties of organic molecules. We have evaluated different computational strategies and models to predict the pK(a) values of substituted phenols using partial atomic charges. Partial atomic charges for 124 phenol molecules were calculated using 83 approaches containing seven theory levels (MP2, HF, B3LYP, BLYP, BP86, AM1, and PM3), three basis sets (6-31G*, 6-311G, STO-3G), and five population analyses (MPA, NPA, Hirshfeld, MK, and Löwdin). The correlations between pK(a) and various atomic charge descriptors were examined, and the best descriptors were selected for preparing the quantitative structure-property relationship (QSPR) models. One QSPR model was created for each of the 83 approaches to charge calculation, and then the accuracy of all these models was analyzed and compared. The pK(a)s predicted by most of the models correlate strongly with experimental pK(a) values. For example, more than 25% of the models have correlation coefficients (R²) greater than 0.95 and root-mean-square errors smaller than 0.49. All seven examined theory levels are applicable for pK(a) prediction from charges. The best results were obtained for the MP2 and HF level of theory. The most suitable basis set was found to be 6-31G*. The 6-311G basis set provided slightly weaker correlations, and unexpectedly also, the STO-3G basis set is applicable for the QSPR modeling of pK(a). The Mulliken, natural, and Löwdin population analyses provide accurate models for all tested theory levels and basis sets. The results provided by the Hirshfeld population analysis were also acceptable, but the QSPR models based on MK charges show only weak correlations.

  8. Bromination of Phenol

    ERIC Educational Resources Information Center

    Talbot, Christopher

    2013-01-01

    This "Science note" examines the bromination of phenol, a reaction that is commonly taught at A-level and IB (International Baccalaureate) as an example of electrophilic substitution. Phenol undergoes bromination with bromine or bromine water at room temperature. A white precipitate of 2,4,6-tribromophenol is rapidly formed. This…

  9. Deprotonation and reductive addition reactions of hypervalent aluminium dihydride compounds containing substituted pyrrolyl ligands with phenols, ketones, and aldehydes.

    PubMed

    Chen, I-Chun; Ho, Shi-Mau; Chen, Ya-Chi; Lin, Che-Yu; Hu, Ching-Han; Tu, Cheng-Yi; Datta, Amitabha; Huang, Jui-Hsien; Lin, Chia-Her

    2009-10-28

    The reactivities of [C4H2N(CH2NMe2)2]AlH2 (1) with primary and secondary amines, phenols, ketones, and phenyl isothiocyanate were examined. Reactions of 1 with one or two equivalents of 2,6-dichloroaniline in methylene chloride generated [C4H2N(CH2NMe2)2]AlH(NHC6H3-2,6-Cl2) (2) and [C4H2N(CH2NMe2)2]Al(NHC6H3-2,6-Cl2)2 (3), respectively, following hydrogen elimination. Similarly, the reactions of 1 with one or two equivalents of carbazole afforded [C4H2N(CH2NMe2)2]AlH(NC12H8) (4) or [C4H2N(CH2NMe2)2]Al(NC12H8)2 (5) by deprotonating the acidic N-H of carbazole. Reacting 1 with one equivalent of 2,6-diisopropylphenol in diethyl ether formed an aluminium phenoxo compound [C4H2N(CH2NMe2)2]AlH(OC6H3-2,6-iPr2) (6), by deprotonation of phenol as well with the elimination of one equivalent hydrogen. Further reaction of 6 with one equivalent of 2,4,6-trimethylacetophenone in methylene chloride generated [C4H2N(CH2NMe2)2]Al(OC6H3-2,6-iPr2)[OC(=CH2)(C6H2-2,4,6-Me3)] (7) by deprotonating the methyl proton of the acetophenone. Similar deprotonation occurred when 1 reacted with two equivalents of 2,4,6-trimethylacetophenone in methylene chloride to generate [C4H2N(CH2NMe2)2]Al[OC(=CH2)(C6H2-2,4,6-Me3)]2 (8). Compounds [C4H2N(CH2NMe2)2]Al(OCHPh2)2 (9), and [C4H2N(CH2NMe2)2]Al(SCHNPh)2 (10) could also be obtained by reacting 1 with two equivalents of benzophenone and phenyl isothiocyanate, respectively through hydroalumination. The 1H NMR spectra of 10 showed broad signals for the CH2N and NMe2 groups, which represent dynamical fluctuations of the molecules in solution state. The estimated energy barrier (DeltaG(c)(double dagger)) from the coalescence temperature for the fluctuation was estimated at 17.1 Kcal mol(-1). The solid-state structures of compounds 2, 3, 5, 7, 9, and 10 have been determined.

  10. Synergistic interplay of a non-heme iron catalyst and amino acid coligands in H2 O2 activation for asymmetric epoxidation of α-alkyl-substituted styrenes.

    PubMed

    Cussó, Olaf; Ribas, Xavi; Lloret-Fillol, Julio; Costas, Miquel

    2015-02-23

    Highly enantioselective epoxidation of α-substituted styrenes with aqueous H2 O2 is described by using a chiral iron complex as the catalyst and N-protected amino acids (AAs) as coligands. The amino acids synergistically cooperate with the iron center in promoting an efficient activation of H2 O2 to catalyze epoxidation of this challenging class of substrates with good yields and stereoselectivities (up to 97%ee) in short reaction times.

  11. Mononuclear zinc(II) complexes of 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols: Synthesis, structural characterization, DNA binding and cheminuclease activities

    NASA Astrophysics Data System (ADS)

    Ravichandran, J.; Gurumoorthy, P.; Karthick, C.; Kalilur Rahiman, A.

    2014-03-01

    Four new zinc(II) complexes [Zn(HL1-4)Cl2] (1-4), where HL1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, have been isolated and fully characterized using various spectro-analytical techniques. The X-ray crystal structure of complex 4 shows the distorted trigonal-bipyramidal coordination geometry around zinc(II) ion. The crystal packing is stabilized by intermolecular NH⋯O hydrogen bonding interaction. The complexes display no d-d electronic band in the visible region due to d10 electronic configuration of zinc(II) ion. The electrochemical properties of the synthesized ligands and their complexes exhibit similar voltammogram at reduction potential due to electrochemically innocent Zn(II) ion, which evidenced that the electron transfer is due to the nature of the ligand. Binding interaction of complexes with calf thymus DNA was studied by UV-Vis absorption titration, viscometric titration and cyclic voltammetry. All complexes bind with CT DNA by intercalation, giving the binding affinity in the order of 2 > 1 ≫ 3 > 4. The prominent cheminuclease activity of complexes on plasmid DNA (pBR322 DNA) was observed in the absence and presence of H2O2. Oxidative pathway reveals that the underlying mechanism involves hydroxyl radical.

  12. Antioxidant, DNA binding and nuclease activities of heteroleptic copper(II) complexes derived from 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols and diimines

    NASA Astrophysics Data System (ADS)

    Ravichandran, J.; Gurumoorthy, P.; Imran Musthafa, M. A.; Kalilur Rahiman, A.

    2014-12-01

    A series of heteroleptic copper(II) complexes of the type [CuL1-4(diimine)](ClO4)2 (1-8) [L1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen)], have been synthesized and characterized by spectroscopic methods. The IR spectra of complexes indicate the presence of uncoordinated perchlorate anions and the electronic spectra revealed the square pyramidal geometry with N4O coordination environment around copper(II) nuclei. Electrochemical studies of the mononuclear complexes evidenced one-electron irreversible reduction wave in the cathodic region. The EPR spectra of complexes with g|| (2.206-2.214) and A|| (154-172 × 10-4 cm-1) values support the square-based CuN3O coordination chromophore and the presence of unpaired electron localized in dx-y ground state. Antioxidant studies against DPPH revealed effective radical scavenging properties of the synthesized complexes. Binding studies suggest that the heteroleptic copper(II) complexes interact with calf thymus DNA (CT-DNA) through minor-groove and electrostatic interaction, and all the complexes display pronounced nuclease activity against supercoiled pBR322 DNA.

  13. Calculating pKa values for substituted phenols and hydration energies for other compounds with the first-order Fuzzy-Border continuum solvation model.

    PubMed

    Sharma, Ity; Kaminski, George A

    2012-11-15

    We have computed pK(a) values for 11 substituted phenol compounds using the continuum Fuzzy-Border (FB) solvation model. Hydration energies for 40 other compounds, including alkanes, alkenes, alkynes, ketones, amines, alcohols, ethers, aromatics, amides, heterocycles, thiols, sulfides, and acids have been calculated. The overall average unsigned error in the calculated acidity constant values was equal to 0.41 pH units and the average error in the solvation energies was 0.076 kcal/mol. We have also reproduced pK(a) values of propanoic and butanoic acids within about 0.1 pH units from the experimental values by fitting the solvation parameters for carboxylate ion carbon and oxygen atoms. The FB model combines two distinguishing features. First, it limits the amount of noise which is common in numerical treatment of continuum solvation models by using fixed-position grid points. Second, it uses either second- or first-order approximation for the solvent polarization, depending on a particular implementation. These approximations are similar to those used for solute and explicit solvent fast polarization treatment which we developed previously. This article describes results of using the first-order technique. This approximation places the presented methodology between the Generalized Born and Poisson-Boltzmann continuum solvation models with respect to their accuracy of reproducing the many-body effects in modeling a continuum solvent.

  14. [Branch-specific detection of phenols and assessment of ground water solubility].

    PubMed

    Fischer, F; Kerndorff, H; Kühn, S

    2000-01-01

    are possible. Input of phenols on agricultural lands can be caused by pesticides, sewage sludge or manure. The groundwater downstream of landfills often contains phenol, chlorophenols, cresols, and xylenols. The formation of phenol from other organic contaminants as benzene in groundwater has been reported. The potential for mobilization of phenols in the saturated zone can be estimated from their physical and chemical properties. Especially low molecular weight phenols are easily mobilized due to their high solubility in water and low potential for accumulation. These compounds are: phenol, cresols, xylenols, chlorophenols, hydroxybenzenes, nitrophenols, anisidines, aminophenols, anisol, 2-phenoxyethanol, and thiophenol. The stability of phenols under laboratory conditions varies. The complete mineralization depends mainly on the experimental set-up, i.e. nutrients, temperature, and type of inocula. The anaerobic degradation of phenols is generally slower than the aerobic. Phenol is readily biodegradable under both aerobic and anaerobic conditions. In general, the biodegradability depends on the type, number and position of substitutes. Phenols with nitro-, alkyl-, or chlorosubstitutes are more recalcitrant than phenol itself. Our biodegradability test show that the decomposition of alkylphenols is determined by the length and branching of the alcyllic chain. Phenols with high contamination potential are chlorophenols, xylenols, and nitrophenols. These compounds are both mobile and recalcitrant in the saturated zone. Phenolic compounds of a medium contamination risk are dichlorophenols, trichlorophenols, cresols, and phenol because they are mobile but less stable in groundwater. These compounds are known contaminants in the groundwater at gasworks, landfills, and ammunition factories. Aminophenols, anisidines, tert-butylphenols, ethylphenols, hydroxybenzenes, and 2-phenoxyethanol also constite a potential hazard for groundwater; however, no contaminations with these

  15. Alkyl group dependence on structure and magnetic properties in layered cobalt coordination polymers containing substituted glutarate ligands and 4,4'-bipyridine

    SciTech Connect

    Nettleman, Joseph H.; Supkowski, Ronald M.; LaDuca, Robert L.

    2010-02-15

    Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared hydrothermally and structurally characterized by single-crystal X-ray diffraction. [Co(mg)(bpy)]{sub n} (1, mg=3-methylglutarate) forms a (4,4) rhomboid grid structure based on the connection of {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} dimeric units. Using the more sterically encumbered ligands 3,3-dimethylglutarate (dmg) and 3-ethyl, 3-methylglutarate (emg) generated {l_brace}[Co(dmg)(bpy)(H{sub 2}O)].2H{sub 2}O{r_brace}{sub n} (2) and {l_brace}[Co(emg)(bpy)(H{sub 2}O)].H{sub 2}O{r_brace}{sub n} (3), respectively. These complexes manifest {l_brace}Co(CO{sub 2}){r_brace}{sub n} chains linked into 2-D by aliphatic dicarboxylate and bpy ligands. The 'tied-back' substituted glutarate ligand 1,1-cyclopentanediacetate (cda) afforded [Co(cda)(bpy)]{sub n} (4), and the unsubstituted glutarate (glu) generated [Co(glu)(bpy)]{sub n} (5), both of which exhibit a topology similar to that of 1. The magnetic properties of complexes 1-4 were analyzed successfully with a recently developed phenomenological chain model accounting for both magnetic coupling (J) and zero-field splitting effects (D), even though 1 and 4 contain isolated, discrete {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} dimers. The D parameter in this series varied between 21.8(8) and 48.0(9) cm{sup -1}. However weak antiferromagnetic coupling was observed in 1 (J=-2.43(4) cm{sup -1}) and 4 (J=-0.89(2) cm{sup -1}), while weak ferromagnetic coupling appears to be operative in both 2 (J=0.324(5) cm{sup -1}) and 3 (J=0.24(1) cm{sup -1}). - Five two-dimensional divalent cobalt coordination polymers containing 4,4'-bipyridine (bpy) and substituted or unsubstituted glutarate ligands have been prepared and structurally characterized by single-crystal X-ray diffraction. Three contain dimeric {l_brace}Co{sub 2}(CO{sub 2}){sub 2}{r_brace} units, while two

  16. Thermochemical properties of methyl-substituted cyclic alkyl ethers and radicals for oxiranes, oxetanes, and oxolanes: C-H bond dissociation enthalpy trends with ring size and ether site.

    PubMed

    Auzmendi-Murua, Itsaso; Charaya, Sumit; Bozzelli, Joseph W

    2013-01-17

    Cyclic ethers are an important product from the gas-phase reactions of hydrocarbon radicals with molecular oxygen in the atmospheric chemistry of diolefins and in low to moderate temperature combustion and oxidation reaction systems. They are also important in organic synthesis. Structures, and fundamental thermochemical parameters-enthalpy (ΔH°(f,298)), entropy (S°(298)), and heat capacity (C(p)(T))-have been calculated for a series of cyclic alkyl ethers and their carbon centered radicals. Enthalpies of formation (ΔH°(f,298)) are determined at the B3LYP/6-31G(d,p), B3LYP/6-31G(2d,2p), and CBS-QB3 levels using several work reactions for each species. Entropy (S) and heat capacity (C(p)(T)) values from vibration, translational, and external rotational contributions are calculated using the rigid-rotor-harmonic-oscillator approximation based on the vibration frequencies and structures obtained from the density functional studies. Contributions from the internal methyl rotors are substituted for torsion frequencies. Calculated enthalpies of formation for a series of 12 cyclic ethers and methyl substituted cyclic ethers are in good agreement with available literature values. C-H bond dissociation enthalpies are reported for 28 carbon sites of 3 to 5 member ring cyclic ethers for use in understanding effects of the ring and the ether oxygen on kinetics and stability. Trends in carbon-hydrogen bond energies for the ring and methyl substituents relative to ring size and to distance from the ether group are described.

  17. 40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721.10679 Section 721... Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester... identified generically as carboxylic acid, substituted alkylstannylene ester, reaction products...

  18. Phenol esterase activity of porcine skin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alkyl esters of plant-derived phenols may serve as slow-release sources for cutaneous delivery of antioxidants. The ability of skin esterases to hydrolyze phenolic esters was examined. Esters of tyrosol and hydroxytyrosol were prepared from decanoic and lipoic acids. Ferulic acid was esterified ...

  19. Polymethylated DOTA ligands. 1. Synthesis of rigidified ligands and studies on the effects of alkyl substitution on acid-base properties and conformational mobility.

    PubMed

    Ranganathan, Ramachandran S; Pillai, Radhakrishna K; Raju, Natarajan; Fan, Helen; Nguyen, Hanh; Tweedle, Michael F; Desreux, Jean F; Jacques, Vincent

    2002-12-16

    This work describes the synthesis and the conformational properties of new polymethylated macrocyclic ligands of potential interest for magnetic resonance imaging. M4cyclen, (2S,5S,8S,11S)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecane, was obtained by cyclotetramerization of (2S)-1-benzyl-2-methylaziridine followed by catalytic hydrogenation. The ligands M4DOTA, [(2S,5S,8S,11S)-4,7,10-tris-carboxymethyl-2,5,8,11-tetramethyl- 1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, and M4DOTMA, (R)-2-[(2S,5S,8S,11S)-4,7,10-tris-((R)-1-carboxyethyl)-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, were prepared by carboxyalkylation of M4cyclen in the presence of Na(2)CO(3). The triacetic ligand M4DO3A, [(2S,5S,8S,11S)-4,7-bis-carboxymethyl-2,5,8,11-tetramethyl-1,4,7,10-tetraazacyclododecan-1-yl]acetic acid, was obtained in good yields without traces of M4DOTA if NaHCO(3) was the acid scavenger when adding the carboxylic arms. In the same conditions, cyclen yielded M4DOTA in 82% yield. The difference between the reactivity of cyclen and M4cyclen is assigned to the high basicity of the substituted tetraamine as estimated by NMR titration. The one- and two-dimensional (1)H and (13)C NMR spectra of M4DOTA and M4DOTMA in the H(4)L or H(6)L(2+) forms are interpreted as arising from a slow exchange between two elongated geometries in which the methyl substituents are in one of the two possible equatorial-like positions, either close to or away from the carboxylic arms. The axial-like positions are sterically too crowded and cannot be occupied by the methyl groups. An elongated conformation is also adopted by DOTMA, (R)-2-[4,7,10-tris-((R)-carboxyethyl)-1,4,7,10-tetraazacyclododecan-1-yl]propionic acid, in the H(6)L(2+) form. The rigidification of the polymethylated ligands allows a detailed NMR analysis that cannot be carried out on the parent unsubstituted ligand DOTA.

  20. Palladium-Catalyzed Cross Coupling of Secondary and Tertiary Alkyl Bromides with a Nitrogen Nucleophile

    PubMed Central

    2016-01-01

    We report a new class of catalytic reaction: the thermal substitution of a secondary and or tertiary alkyl halide with a nitrogen nucleophile. The alkylation of a nitrogen nucleophile with an alkyl halide is a classical method for the construction of C–N bonds, but traditional substitution reactions are challenging to achieve with a secondary and or tertiary alkyl electrophile due to competing elimination reactions. A catalytic process could address this limitation, but thermal, catalytic coupling of alkyl halides with a nitrogen nucleophile and any type of catalytic coupling of an unactivated tertiary alkyl halide with a nitrogen nucleophile are unknown. We report the coupling of unactivated secondary and tertiary alkyl bromides with benzophenone imines to produce protected primary amines in the presence of palladium ligated by the hindered trialkylphosphine Cy2t-BuP. Mechanistic studies indicate that this amination of alkyl halides occurs by a reversible reaction to form a free alkyl radical. PMID:27725963

  1. Direct, Regioselective N-Alkylation of 1,3-Azoles.

    PubMed

    Chen, Shuai; Graceffa, Russell F; Boezio, Alessandro A

    2016-01-04

    Regioselective N-alkylation of 1,3-azoles is a valuable transformation. Organomagnesium reagents were discovered to be competent bases to affect regioselective alkylation of various 1,3-azoles. Counterintuitively, substitution selectively occurred at the more sterically hindered nitrogen atom. Numerous examples are provided, on varying 1,3-azole scaffolds, with yields ranging from 25 to 95%.

  2. Synthesis of substituted pyrazines

    SciTech Connect

    Pagoria, Philip F.; Zhang, Mao Xi

    2016-10-04

    A method for synthesizing a pyrazine-containing material according to one embodiment includes contacting an iminodiacetonitrile derivative with a base and a reagent selected from a group consisting of hydroxylamine, a hydroxylamine salt, an aliphatic primary amine, a secondary amine, an aryl-substituted alkylamine a heteroaryl-substituted alkyl amine, an alcohol, an alkanolamine and an aryl alcoholamine. Additional methods and several reaction products are presented. ##STR00001##

  3. Regioselective 1-N-Alkylation and Rearrangement of Adenosine Derivatives.

    PubMed

    Oslovsky, Vladimir E; Drenichev, Mikhail S; Mikhailov, Sergey N

    2015-01-01

    Several methods for the preparation of some N(6)-substituted adenosines based on selective 1-N-alkylation with subsequent Dimroth rearrangement were developed. The proposed methods seem to be effective for the preparation of natural N(6)-isopentenyl- and N(6)-benzyladenosines, which are known to possess pronounced biological activities. Direct 1-N-alkylation of 2',3',5'-tri-O-acetyladenosine and 3',5'-di-O-acetyl-2'-deoxyadenosine with alkyl halides in N,N-dimethylformamide (DMF) in the presence of BaCO3 and KI gave 1-N-substituted derivatives with quantitative yields, whereas 1-N-alkylation of adenosine was accompanied by significant O-alkylation. Moreover, the reaction of trimethylsilyl derivatives of N(6)-acetyl-2',3',5'-tri-O-acetyladenosine and N(6)-acetyl-3',5'-di-O-acetyl-2'-deoxyadenosine with alkyl halides leads to the formation of the stable 1-N-substituted adenosines. Dimroth rearrangement of 1-N-substituted adenosines in aqueous ammonia yields pure N(6)-substituted adenosines.

  4. Headspace-single drop microextraction (HS-SDME) in combination with high-performance liquid chromatography (HPLC) to evaluate the content of alkyl- and methoxy-phenolic compounds in biomass smoke.

    PubMed

    Rincón, Arturo A; Pino, Verónica; Ayala, Juan H; Afonso, Ana M

    2011-09-15

    The content of ten phenolic compounds present in four different biomass smoke materials: rock rose (Cistus monpelienisis), prickly pear (Opuntia ficus indica), pine needles (Pinus canariensis), and almonds skin (Prunus dulcis), have been evaluated. The sampling method mainly consisted of a trap alkaline solution to solubilize the phenols, and was optimized by an experimental design. Average sampling efficiencies of 78.1% and an average precision value of 10.6% (as relative standard deviation, RSD), were obtained for the selected group of phenols. The trapped phenolates were further analyzed by a headspace-single drop microextraction (HS-SDME) procedure, in combination with high-performance liquid chromatography (HPLC) with UV detection. The optimum variables for the HS-SDME method were: 1-decanol as extractant solvent, 3.5 μL of microdrop volume, 2 mL of sample volume, a pH value of 2, saturation of NaCl, an extraction temperature of 60°C, and an extraction time of 25 min. The optimized HS-SDME method presented detection limits ranging from 0.35 to 5.8 μg mL(-1), RSD values ranging from 0.7 to 7.4%, and an average relative recovery (RR) of 99.8% and an average standard deviation of 5.2. The average content of phenolic compounds in the biomass materials studied were 70, 161, 206 and 252 mg kg(-1) of biomass for prickly pear, almonds skin, rock rose, and pine needles, respectively. The main components of the smokes were vanillin, phenol and methoxyphenols, in all smoking materials studied.

  5. Synthesis and activity of substituted 4-(indazol-3-yl)phenols as pathway-selective estrogen receptor ligands useful in the treatment of rheumatoid arthritis.

    PubMed

    Steffan, Robert J; Matelan, Edward; Ashwell, Mark A; Moore, William J; Solvibile, William R; Trybulski, Eugene; Chadwick, Christopher C; Chippari, Susan; Kenney, Thomas; Eckert, Amy; Borges-Marcucci, Lisa; Keith, James C; Xu, Zhang; Mosyak, Lydia; Harnish, Douglas C

    2004-12-16

    Pathway-selective ligands for the estrogen receptor (ER) inhibit NF-kappaB-mediated inflammatory gene expression causing a reduction of cytokines, chemokines, adhesion molecules, and inflammatory enzymes. SAR development of a series of 4-(indazol-3-yl)phenols has led to the identification of WAY-169916 an orally active nonsteroidal ligand with the potential use in the treatment of rheumatoid arthritis without the classical proliferative effects associated with estrogens.

  6. Crystal structures of copper(II) nitrate complexes containing 4,4'-bipyridyl and halogen-substituted 2-[(2-hydroxyethylimino)methyl]phenols

    SciTech Connect

    Chumakov, Yu. M.; Tsapkov, V. I.; Petrenko, P. A.; Popovski, L. G.; Simonov, Yu. A.; Bocelli, G.; Gulea, A. P.

    2009-03-15

    The crystal structures of ({mu}-4,4'-bipyridyl)-di{l_brace}nitrato-2,4-dibromo-6-[(2-hydroxyethylimino)methyl] phenolo (1-)copper{r_brace} (I), ({mu}-4,4'-bipyridyl)-di{l_brace}nitrato-2,4-dichloro-6-[(2-hydroxyethylimino)methyl] phenolo(1-)copper{r_brace} (II), and ({mu}-4,4'-bipyridyl)-{l_brace}4-chloro-2-[(2-hydroxyethylimino)methyl]phenolo(2-) copper-nitrato-4-chloro-2-[(2-hydroxyethylimino)methyl]phenolo(1-)copper{r_brace} tetrahydrate (III) are determined. The crystal structures of compounds I and II contain binuclear complexes, in which each copper atom is coordinated by the singly deprotonated tridentate molecule of the corresponding azomethine, the monodentate nitrate ion, and bipyridyl that plays the role of a bridge between the central atoms. In the structures of compounds I and II, the coordination polyhedra of the copper atoms are slightly distorted tetragonal pyramids. The pyramid base is formed by the imine and bipyridyl nitrogen atoms and the phenol and alcohol oxygen atoms. The axial vertices of the pyramids are occupied by the oxygen atoms of the monodentate nitrato groups. The crystal structure of compound III involves tetranuclear complexes in which the coordination polyhedra of the central copper atoms are (4 + 1 + 1) bipyramids. The base of these bipyramids is formed by the imine and bipyridyl nitrogen atoms and the phenol and alcohol oxygen atoms. One apical vertex is occupied by the bridging phenol oxygen atom of the nearest complex. The sixth coordination site of the first copper atom is occupied by the chlorine atom of the salicylidene fragment of the neighboring complex related to the initial complex through the center of symmetry. In turn, the sixth coordination site of the second copper atom is occupied by the oxygen atom of the monodentate nitrato group.

  7. Antihydrophobic cosolvent effects for alkylation reactions in water solution, particularly oxygen versus carbon alkylations of phenoxide ions.

    PubMed

    Breslow, Ronald; Groves, Kevin; Mayer, M Uljana

    2002-04-10

    Antihydrophobic cosolvents such as ethanol increase the solubility of hydrophobic molecules in water, and they also affect the rates of reactions involving hydrophobic surfaces. In simple reactions of hydrocarbons, such as the Diels-Alder dimerization of 1,3-cyclopentadiene, the rate and solubility data directly reflect the geometry of the transition state, in which some hydrophobic surface becomes hidden. In reactions involving polar groups, such as alkylations of phenoxide ions or S(N)1 ionizations of alkyl halides, cosolvents in water can have other effects as well. However, solvation of hydrophobic surfaces is still important. By the use of structure-reactivity relationships, and comparing the effects of ethanol and DMSO as solvents, it has been possible to sort out these effects. The conclusions are reinforced by an ab initio computer model for hydrophobic solvation. The result is a sensible transition state for phenoxide ion as a nucleophile, using its oxygen n electrons to avoid loss of conjugation. The geometry of alkylation of aniline is very different, involving packing (stacking) of the aniline ring onto the phenyl ring of a benzyl group in the benzylation reaction. The alkylation of phenoxide ions by benzylic chlorides can occur both at the phenoxide oxygen and on ortho and para positions of the ring. Carbon alkylation occurs in water, but not in nonpolar organic solvents, and it is observed only when the phenoxide has at least one methyl substituent ortho, meta, or para. The effects of phenol substituents and of antihydrophobic cosolvents on the rates of the competing alkylation processes indicate that in water the carbon alkylation involves a transition state with hydrophobic packing of the benzyl group onto the phenol ring. The results also support our conclusion that oxygen alkylation uses the n electrons of the phenoxide oxygen as the nucleophile and does not have hydrophobic overlap in the transition state. The mechanisms and explanations for

  8. Enantioselective Reactions of 2-Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho-Quinone Methide Intermediates.

    PubMed

    Chen, Ping; Wang, Kai; Guo, Wengang; Liu, Xianghui; Liu, Yan; Li, Can

    2017-03-20

    We report herein a dynamic kinetic resolution (DKR) involving ortho-quinone methide (o-QM) intermediates. In the presence of Et3 N and the cinchonine-derived nucleophilic catalyst D, the DKR of 2-sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57-79 % yield with good to excellent enantioselectivity (85-95 % ee). Furthermore, with 2-(tosylmethyl)sesamols or 2-(tosylmethyl)naphthols, from which stable o-QM substrates can be generated, a formal [4+2] cycloaddition delivered 4-aryl- or alkyl-substituted chromans with excellent enantioselectivity (88-97 % ee).

  9. Synthesis and Antioxidant Activity of Hydroxytyrosol Alkyl-Carbonate Derivatives.

    PubMed

    Fernandez-Pastor, Ignacio; Fernandez-Hernandez, Antonia; Rivas, Francisco; Martinez, Antonio; Garcia-Granados, Andres; Parra, Andres

    2016-07-22

    Three procedures have been investigated for the isolation of tyrosol (1) and hydroxytyrosol (2) from a phenolic extract obtained from the solid residue of olive milling. These three methods, which facilitated the recovery of these phenols, were chemical or enzymatic acetylation, benzylation, and carbomethoxylation, and subsequent carbonylation or acetonation reactions. Several new lipophilic alkyl-carbonate derivatives of hydroxytyrosol have been synthesized, coupling the primary hydroxy group of this phenol, through a carbonate linker, using alcohols with different chain lengths. The antioxidant properties of these lipophilic derivatives have been evaluated by different methods and compared with free hydroxytyrosol (2) and also with the well-known antioxidants BHT and α-tocopherol. Three methods were used for the determination of this antioxidant activity: FRAP and ABTS assays, to test the antioxidant power in hydrophilic media, and the Rancimat test, to evaluate the antioxidant capacity in a lipophilic matrix. These new alkyl-carbonate derivatives of hydroxytyrosol enhanced the antioxidant activity of this natural phenol, with their antioxidant properties also being higher than those of the commercial antioxidants BHT and α-tocopherol. There was no clear influence of the side-chain length on the antioxidant properties of the alkyl-carbonate derivatives of 2, although the best results were achieved mainly by the compounds with a longer chain on the primary hydroxy group of this natural phenolic substance.

  10. Pharmacokinetics of wood creosote: glucuronic acid and sulfate conjugation of phenolic compounds.

    PubMed

    Ogata, N; Matsushima, N; Shibata, T

    1995-09-01

    Wood creosote, principally a mixture of non-, alkyl- and/or alkoxy-substituted phenolic compounds, was orally administered to adult male volunteers to determine its metabolites and pharmacokinetic parameters. After a 133-mg single dose, its major constituents (i.e. phenol 15 mg, guaiacol 32 mg, p-cresol 18 mg and creosol 24 mg) were found in peripheral venous blood and urine, mostly as glucuronic acid and, except for creosol, as sulfate conjugates. Low concentrations of unconjugated phenols were also detected. The metabolites in the serum started to increase 15 min after the dose, and they reached their maximum concentrations 30 min after administration. The maximum concentrations of glucuronides were 0.18 +/- 0.07, 0.91 +/- 0.38, 0.33 +/- 0.18 and 0.47 +/- 0.23 mg/l; those of sulfates were 0.16 +/- 0.06, 0.22 +/- 0.09, 0.17 +/- 0.07 and < 0.04 mg/l for phenol, guaiacol, p-cresol and creosol, respectively. The 24-hour urinary recoveries of the sum of each compound and its metabolites were 75 +/- 35, 45 +/- 36, 103 +/- 51 and 74 +/- 36%, in the above order. The presence of guaiacol glucuronide in blood and urine was directly verified by its isolation and structure analyses.

  11. Synthesis and antiviral activity of some C2-, C4-, and C6-substituted pyrazolo[3,4-D]pyrimidine acyclonucleosides with the alkylating chains of ACV, HBG, and ISO-DHPG.

    PubMed

    Moukha-Chafiq, Omar; Taha, Mohamed Labd; Lazrek, Hassan Bihi; Vasseur, Jean-Jacques; Clercq, Erik De

    2006-01-01

    A useful route to obtain trisubstituted pyrazolo[3,4-d]pyrimidines 14-17 is described. Those later were coupled with the alkylating agents 18-20 as in ACV, HBG, and iso-DHPG to give, after deprotection, the desired acylonucleosides 33-44. Almost all of the new compounds were evaluated for their inhibitory effects against the replication of various DNA viruses in culture.

  12. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  13. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  14. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721.10108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic)....

  15. Facile C-H alkylation in water: enabling defect-free materials for optoelectronic devices.

    PubMed

    Saikia, Gunin; Iyer, Parameswar K

    2010-04-16

    A facile method for the alkylation of fluorene achieved via direct C-H alkylation under aqueous conditions is reported, wherein the formation of fluorenone is inhibited, resulting in the exclusive formation of the desired dialkyl-substituted fluorene monomer. As a proof of concept, this method has also been successfully extended to perform N-alkylation of carbazole, diphenylamine, and N,N-dialkylation of aniline in high yields.

  16. Copper-catalyzed intermolecular carboetherification of unactivated alkenes by alkyl nitriles and alcohols.

    PubMed

    Chatalova-Sazepin, Claire; Wang, Qian; Sammis, Glenn M; Zhu, Jieping

    2015-04-27

    A three-component carboetherification of unactivated alkenes has been developed allowing the rapid building of complexity from simple starting materials. A wide range of α-substituted styrenes underwent smooth reactions with unactivated alkyl nitriles and alcohols to afford γ-alkoxy alkyl nitriles with concomitant generation of a quaternary carbon center. A radical clock experiment provided clear-cut evidence that the reaction proceeds through a tertiary alkyl radical intermediate.

  17. Synthesis and characterization of chitosan alkyl urea.

    PubMed

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations.

  18. Antibacterial activities of 4-substituted-2-[(E)-{(1S,2R)/(1R,2S)-1-hydroxy-1-phenylpropan-2-ylimino}methyl]phenol.

    PubMed

    Tamizh, Manoharan Muthu; Kesavan, Devarayan; Sivakumar, Ponnurengam Malliappan; Mereiter, Kurt; Deepa, Mohan; Kirchner, Karl; Doble, Mukesh; Karvembu, Ramasamy

    2012-02-01

    A series of norephedrine-based Schiff bases (1a-6a and 1b-6b) were synthesized by reacting substituted salicylaldehydes with d-norephedrine or l-norephedrine. The structure of these compounds was confirmed by elemental analyses and spectroscopic techniques. The molecular structures of 5a and 6a have been determined by X-ray crystallography, which revealed that the compounds are in the oxoamino form, with bent intramolecular N-H···O (N···O ≈ 2.58 Å) hydrogen bonds and that they are associated in dimers bridged by linear intermolecular O-H···O (O···O ≈ 2.69 Å) hydrogen bonds. The density functional theory calculations on 5a confirmed that the oxoamino form is more stable than the phenolimino form by 12.2 kcal/mol. All the compounds were evaluated for their antibacterial activity using resazurin dye as indicator by twofold dilution method against four bacteria namely, Bacillus subtilis (NCIM2718), Staphylococcus aureus (NCIM5021), Escherichia coli (NCIM2931), and Proteus vulgaris (NCIM2813).

  19. Synthesis Of Alkyl Hydroperoxides Via Alkylation Of gem-Dihydroperoxides

    PubMed Central

    Kyasa, ShivaKumar; Puffer, Benjamin W.

    2013-01-01

    Two-fold alkylation of 1,1-dihydroperoxides, followed by hydrolysis of the resulting bisperoxyacetals, provides a convenient method for synthesis of primary and secondary alkyl hydroperoxides. PMID:23469994

  20. Ultrafiltration of micellar solutions containing phenols

    SciTech Connect

    Adamczak, H.; Materna, K.; Urbanski, R.; Szymanowski, J.

    1999-10-15

    Micellar-enhanced ultrafiltration represents a potentially attractive tool for the removal of different contaminants from wastewaters. The ultrafiltration of micellar solutions containing phenol or 4-nitrophenol was studied. Sodium dodecyl sulfate (SDS), hexadecylrimethyl ammonium sulfate, alkyl polyglucoside Glucopon 215 SC UP, and oxyethylated methyl dodecanoates with the average degree of oxyethylation equal to 5 and 9 were used as surfactants and NaHCO{sub 3} as an electrolyte and alkalizing agent. Filtration and phenol rejection depends on the presence of NaHCO{sub 3} and the type of surfactant. NaHCO{sub 3} depresses to the filtration rate, especially in the case of SDS and hydrophobic oxyethylated methyl dodecanoate. The highest filtration rates are obtained for hexadecyltrimethyl ammonium bromide (CTAB) and alkyl polyglucoside micellar solutions. The best separations, both of phenol and 4-nitrophenol (almost 100% rejection), are obtained for CTAB micellar solutions at the pH range from 3 to 11. Nonionic surfactants are not effective enough for the separation of phenol and 4-nitrophenol. SDS solutions permit only the separation of phenol.

  1. Organochalcogen substituents in phenolic antioxidants.

    PubMed

    Amorati, Riccardo; Pedulli, Gian Franco; Valgimigli, Luca; Johansson, Henrik; Engman, Lars

    2010-05-21

    Little is known about the ED/EW character of organochalcogen substituents and their contribution to the O-H bond dissociation enthalpy (BDE) in phenolic compounds. A series of ortho- and para-(S,Se,Te)R-substituted phenols were prepared and investigated by EPR, IR, and computational methods. Substituents lowered the O-H BDE by >3 kcal/mol in the para position, while the ortho-effect was modest due to hydrogen bonding ( approximately 3 kcal/mol) to the O-H group.

  2. General allylic C-H alkylation with tertiary nucleophiles.

    PubMed

    Howell, Jennifer M; Liu, Wei; Young, Andrew J; White, M Christina

    2014-04-16

    A general method for intermolecular allylic C-H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C-H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C-H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C-H reactivity are illustrated in an allylic C-H alkylation/Diels-Alder reaction cascade: a reactive diene is generated via intermolecular allylic C-H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids.

  3. Influence of the ligand alkyl chain length on the solubility, aqueous speciation, and kinetics of substitution reactions of water-soluble M3S4 (M = Mo, W) clusters bearing hydroxyalkyl diphosphines.

    PubMed

    Beltrán, Tomás F; Llusar, Rosa; Sokolov, Maxim; Basallote, Manuel G; Fernández-Trujillo, M Jesús; Pino-Chamorro, Jose Ángel

    2013-08-05

    Water-soluble [M3S4X3(dhbupe)3](+) diphosphino complexes (dhbupe = 1,2-bis(bis(hydroxybutyl)phosphino)ethane), 1(+) (M = Mo, X = Cl) and 2(+) (M = W; X = Br), have been synthesized by extending the procedure used for the preparation of their hydroxypropyl analogues by reaction of the M3S4(PPh3)3X4(solvent)x molecular clusters with the corresponding 1,2-bis(bishydroxyalkyl)diphosphine. The solid state structure of the [M3S4X3(dhbupe)3](+) cation possesses a C3 symmetry with a cuboidal M3S4 unit, and the outer positions are occupied by one halogen and two phosphorus atoms of the diphosphine ligand. At a basic pH, the halide ligands are substituted by hydroxo groups to afford the corresponding [Mo3S4(OH)3(dhbupe)3](+) (1OH(+)) and [W3S4(OH)3(dhbupe)3](+) (2OH(+)) complexes. This behavior is similar to that found in 1,2-bis(bis(hydroxymethyl)phosphino)ethane (dhmpe) complexes and differs from that observed for 1,2-bis(bis(hydroxypropyl)phosphino)ethane (dhprpe) derivatives. In the latter case, an alkylhydroxo group of the functionalized diphosphine replaces the chlorine ligands to afford Mo3S4 complexes in which the deprotonated dhprpe acts in a tridentate fashion. Detailed studies based on stopped-flow, (31)P{(1)H} NMR, and electrospray ionization mass spectrometry techniques have been carried out in order to understand the solution behavior and kinetics of interconversion between the different species formed in solution: 1 and 1OH(+) or 2 and 2OH(+). On the basis of the kinetic results, a mechanism with two parallel reaction pathways involving water and OH(-) attacks is proposed for the formal substitution of halides by hydroxo ligands. On the other hand, reaction of the hydroxo clusters with HX acids occurs with protonation of the OH(-) ligands followed by substitution of coordinated water by X(-).

  4. Pervaporation of phenols

    DOEpatents

    Boddeker, K.W.

    1989-02-21

    Aqueous phenolic solutions are separated by pervaporation to yield a phenol-depleted retentate and a phenol-enriched permeate. The separation effect is enhanced by phase segregation into two immiscible phases, phenol in water'' (approximately 10% phenol), and water in phenol'' (approximately 70% phenol). Membranes capable of enriching phenols by pervaporation include elastomeric polymers and anion exchange membranes, membrane selection and process design being guided by pervaporation performance and chemical stability towards phenolic solutions. Single- and multiple-stage processes are disclosed, both for the enrichment of phenols and for purification of water from phenolic contamination. 8 figs.

  5. Pervaporation of phenols

    DOEpatents

    Boddeker, Karl W.

    1989-01-01

    Aqueous phenolic solutions are separated by pervaporation to yield a phenol-depleted retentate and a phenol-enriched permeate. The separation effect is enhanced by phase segregation into two immiscible phases, "phenol in water" (approximately 10% phenol), and "water in phenol" (approximately 70% phenol). Membranes capable of enriching phenols by pervaporation include elastomeric polymers and anion exchange membranes, membrane selection and process design being guided by pervaporation performance and chemical stability towards phenolic solutions. Single- and multiple-stage procresses are disclosed, both for the enrichment of phenols and for purification of water from phenolic contamination.

  6. Degradation of Alkyl Benzene Sulfonate by Pseudomonas Species1

    PubMed Central

    Horvath, R. S.; Koft, B. W.

    1972-01-01

    Pseudomonas sp. HK-1 showed a direct relation between the concentration of alkyl benzene sulfonate (ABS) supplied and cell yields. Since growth on ABS alone did not occur, it was necessary to correlate the total energy obtained by the cells to the ABS concentration when glucose was supplied in a limiting concentration. Several types of metabolic attack in addition to the sulfonate removal were noted: (i) side-chain utilization as indicated by the production of tertiarybutyl alcohol and isopropanol and (ii) ring metabolism as indicated by the presence of phenol, catechol, mandelic acid, benzyl alcohol, and benzoic acid in spent growth media. Utilization of ABS was greatly enhanced by the presence of phenol. This enhancement suggests co-metabolism and that limited concentrations of phenolic products derived from ABS must be accumulated to get active metabolism of the ABS molecule. PMID:5017680

  7. Method of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  8. Alkyl-π engineering in state control toward versatile optoelectronic soft materials

    PubMed Central

    Lu, Fengniu; Nakanishi, Takashi

    2015-01-01

    Organic π-conjugated molecules with extremely rich and tailorable electronic and optical properties are frequently utilized for the fabrication of optoelectronic devices. To achieve high solubility for facile solution processing and desirable softness for flexible device fabrication, the rigid π units were in most cases attached by alkyl chains through chemical modification. Considerable numbers of alkylated-π molecular systems with versatile applications have been reported. However, a profound understanding of the molecular state control through proper alkyl chain substitution is still highly demanded because effective applications of these molecules are closely related to their physical states. To explore the underlying rule, we review a large number of alkylated-π molecules with emphasis on the interplay of van der Waals interactions (vdW) of the alkyl chains and π–π interactions of the π moieties. Based on our comprehensive investigations of the two interactions’ impacts on the physical states of the molecules, a clear guidance for state control by alkyl-π engineering is proposed. Specifically, either with proper alkyl chain substitution or favorable additives, the vdW and π–π interactions can be adjusted, resulting in modulation of the physical states and optoelectronic properties of the molecules. We believe the strategy summarized here will significantly benefit the alkyl-π chemistry toward wide-spread applications in optoelectronic devices. PMID:27877748

  9. Tetrahydroisoquinoline Phenols: Selective Estrogen Receptor Downregulator Antagonists with Oral Bioavailability in Rat

    PubMed Central

    2015-01-01

    A series of tetrahydroisoquinoline phenols was modified to give an estrogen receptor downregulator-antagonist profile. Optimization around the core, alkyl side chain, and pendant aryl ring resulted in compounds with subnanomolar levels of potency. The phenol functionality was shown to be required to achieve highly potent compounds, but unusually this was compatible with obtaining high oral bioavailabilities in rat. PMID:26819673

  10. Regio- and stereoselective 1,2-dihydropyridine alkylation/addition sequence for the synthesis of piperidines with quaternary centers.

    PubMed

    Duttwyler, Simon; Chen, Shuming; Lu, Colin; Mercado, Brandon Q; Bergman, Robert G; Ellman, Jonathan A

    2014-04-07

    The first example of C alkylation of 1,2-dihydropyridines with alkyl triflates and Michael acceptors was developed to introduce quaternary carbon centers with high regio- and diastereoselectivity. Hydride or carbon nucleophile addition to the resultant iminium ion also proceeded with high diastereoselectivity. Carbon nucleophile addition results in an unprecedented level of substitution to provide piperidine rings with adjacent tetrasubstituted carbon atoms.

  11. An efficient Friedel-Crafts/oxa-Michael/aromatic annulation: rapid access to substituted naphtho[2,1-b]furan, naphtho[1,2-b]furan, and benzofuran derivatives.

    PubMed

    Anwar, Shaik; Huang, Wan-Yun; Chen, Chih-Hao; Cheng, You-Song; Chen, Kwunmin

    2013-03-25

    Substituted naphthofurans and benzofurans are easily accessible by treatment of naphthols/substituted phenols with nitroallylic acetates through a substitution-elimination process promoted by cesium carbonate. Reactions between naphthols and aromatic/heteroaromatic-substituted nitroallylic acetates gave the desired functionalized naphthofurans in high to excellent chemical yields (14-97%). On the other hand, treatment of phenol derivatives (i.e., 3-dimethylamino-, 3-methoxy-, and 3,5-dimethoxyphenol) with various nitroallylic acetates afforded the corresponding benzofurans in moderate to good chemical yields (24-91%). The reaction proceeded through an interesting Friedel-Crafts S(N)2' process followed by intramolecular oxa-Michael cyclization and subsequent aromatization. A plot of log (k/kH) against Hammett constants σ(p) showed satisfactory linearity with a positive ρ value, indicating that the initial Friedel-Crafts-type S(N)2' process constituted the rate-determining step. This methodology has been applied to the synthesis of various novel C2 and C3 symmetric bis- and trisfurans by using catechol and phloroglucinol as the nucleophilic partners. The reactivity decreased when alkyl-substituted nitroallylic acetate systems were used. This might be related to the decreased electrophilic character of these substrates.

  12. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  13. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  14. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  15. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  16. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  17. Biocatalytic trifluoromethylation of unprotected phenols

    NASA Astrophysics Data System (ADS)

    Simon, Robert C.; Busto, Eduardo; Richter, Nina; Resch, Verena; Houk, Kendall N.; Kroutil, Wolfgang

    2016-11-01

    Organofluorine compounds have become important building blocks for a broad range of advanced materials, polymers, agrochemicals, and increasingly for pharmaceuticals. Despite tremendous progress within the area of fluorination chemistry, methods for the direct introduction of fluoroalkyl-groups into organic molecules without prefunctionalization are still highly desired. Here we present a concept for the introduction of the trifluoromethyl group into unprotected phenols by employing a biocatalyst (laccase), tBuOOH, and either the Langlois' reagent or Baran's zinc sulfinate. The method relies on the recombination of two radical species, namely, the phenol radical cation generated directly by the laccase and the CF3-radical. Various functional groups such as ketone, ester, aldehyde, ether and nitrile are tolerated. This laccase-catalysed trifluoromethylation proceeds under mild conditions and allows accessing trifluoromethyl-substituted phenols that were not available by classical methods.

  18. Biocatalytic trifluoromethylation of unprotected phenols

    PubMed Central

    Simon, Robert C.; Busto, Eduardo; Richter, Nina; Resch, Verena; Houk, Kendall N.; Kroutil, Wolfgang

    2016-01-01

    Organofluorine compounds have become important building blocks for a broad range of advanced materials, polymers, agrochemicals, and increasingly for pharmaceuticals. Despite tremendous progress within the area of fluorination chemistry, methods for the direct introduction of fluoroalkyl-groups into organic molecules without prefunctionalization are still highly desired. Here we present a concept for the introduction of the trifluoromethyl group into unprotected phenols by employing a biocatalyst (laccase), tBuOOH, and either the Langlois' reagent or Baran's zinc sulfinate. The method relies on the recombination of two radical species, namely, the phenol radical cation generated directly by the laccase and the CF3-radical. Various functional groups such as ketone, ester, aldehyde, ether and nitrile are tolerated. This laccase-catalysed trifluoromethylation proceeds under mild conditions and allows accessing trifluoromethyl-substituted phenols that were not available by classical methods. PMID:27834376

  19. Predicting solvent stability in aprotic electrolyte Li-air batteries: nucleophilic substitution by the superoxide anion radical (O2(•-)).

    PubMed

    Bryantsev, Vyacheslav S; Giordani, Vincent; Walker, Wesley; Blanco, Mario; Zecevic, Strahinja; Sasaki, Kenji; Uddin, Jasim; Addison, Dan; Chase, Gregory V

    2011-11-10

    There is increasing evidence that cyclic and linear carbonates, commonly used solvents in Li ion battery electrolytes, are unstable in the presence of superoxide and thus are not suitable for use in rechargeable Li-air batteries employing aprotic electrolytes. A detailed understanding of related decomposition mechanisms provides an important basis for the selection and design of stable electrolyte materials. In this article, we use density functional theory calculations with a Poisson-Boltzmann continuum solvent model to investigate the reactivity of several classes of aprotic solvents in nucleophilic substitution reactions with superoxide. We find that nucleophilic attack by O(2)(•-) at the O-alkyl carbon is a common mechanism of decomposition of organic carbonates, sulfonates, aliphatic carboxylic esters, lactones, phosphinates, phosphonates, phosphates, and sulfones. In contrast, nucleophilic reactions of O(2)(•-) with phenol esters of carboxylic acids and O-alkyl fluorinated aliphatic lactones proceed via attack at the carbonyl carbon. Chemical functionalities stable against nucleophilic substitution by superoxide include N-alkyl substituted amides, lactams, nitriles, and ethers. The results establish that solvent reactivity is strongly related to the basicity of the organic anion displaced in the reaction with superoxide. Theoretical calculations are complemented by cyclic voltammetry to study the electrochemical reversibility of the O(2)/O(2)(•-) couple containing tetrabutylammonium salt and GCMS measurements to monitor solvent stability in the presence of KO(2)(•) and a Li salt. These experimental methods provide efficient means for qualitatively screening solvent stability in Li-air batteries. A clear correlation between the computational and experimental results is established. The combination of theoretical and experimental techniques provides a powerful means for identifying and designing stable solvents for rechargeable Li-air batteries.

  20. Polyimides with pendant alkyl groups

    NASA Technical Reports Server (NTRS)

    Jensen, B. J.; Young, P. R.

    1982-01-01

    The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

  1. Alkyl polycyclic aromatic hydrocarbons emissions in diesel/biodiesel exhaust

    NASA Astrophysics Data System (ADS)

    Casal, Carina S.; Arbilla, Graciela; Corrêa, Sergio M.

    2014-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely studied in environmental matrices, such as air, water, soil and sediment, because of their toxicity, mutagenicity and carcinogenicity. Because of these properties, the environmental agencies of developed countries have listed sixteen PAHs as priority pollutants. Few countries have limits for these compounds for ambient air, but they only limit emissions from stationary and mobile sources and occupational areas. There are several studies to specifically address the 16 priority PAHs and very little for the alkyl PAHs. These compounds are more abundant, more persistent and frequently more toxic than the non-alkylated PAHs, and the toxicity increases with the number of alkyl substitutions on the aromatic ring. In this study, a method was developed for the analysis of PAHs and alkyl PAHs by using a GC-MS and large injection volume injection coupled with program temperature vaporisation, which allows for limits of detection below 1.0 ng μL-1. Several variables were tested, such as the injection volume, injection velocity, injector initial temperature, duration of the solvent split and others. This method was evaluated in samples from particulate matter from the emissions of engines employing standard diesel, commercial diesel and biodiesel B20. Samples were collected on a dynamometer bench for a diesel engine cycle and the results ranged from 0.5 to 96.9 ng mL-1, indicating that diesel/biodiesel makes a significant contribution to the formation of PAHs and alkyl PAHs.

  2. Scope and limitations of the Heck-Matsuda-coupling of phenol diazonium salts and styrenes: a protecting-group economic synthesis of phenolic stilbenes.

    PubMed

    Schmidt, Bernd; Elizarov, Nelli; Berger, René; Hölter, Frank

    2013-06-14

    4-Phenol diazonium salts undergo Pd-catalyzed Heck reactions with various styrenes to 4'-hydroxy stilbenes. In almost all cases higher yields and fewer side products were observed, compared to the analogous 4-methoxy benzene diazonium salts. In contrast, the reaction fails completely with 2- and 3-phenol diazonium salts. For these substitution patterns the methoxy-substituted derivatives are superior.

  3. Metabolism of alkyl amines by the filamentous fungus Aspergillus versicolor.

    PubMed Central

    Lindley, N D

    1987-01-01

    A variety of monoalkyl-substituted amines were able to act as nitrogen sources for heterotrophically growing cultures of Aspergillus versicolor. Only amines whose alkyl chains were at least five carbon atoms long were capable of supporting significant growth in the absence of a separate carbon substrate. However, biomass yields were significantly higher during growth on glucose-amine than on glucose-ammonia, indicating that some energy-generating dissimilation of the amine to CO2 took place. PMID:3566265

  4. Branch-Selective Alkene Hydroarylation by Cooperative Destabilization: Iridium-Catalyzed ortho-Alkylation of Acetanilides

    PubMed Central

    Crisenza, Giacomo E M; Sokolova, Olga O; Bower, John F

    2015-01-01

    An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine dFppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines, and addresses long-standing issues associated with related Friedel–Crafts alkylations. PMID:26490739

  5. Asymmetric Intramolecular Alkylation of Chiral Aromatic Imines via Catalytic C-H Bond Activation

    SciTech Connect

    Watzke, Anja; Wilson, Rebecca; O'Malley, Steven; Bergman, Robert; Ellman, Jonathan

    2007-04-16

    The asymmetric intramolecular alkylation of chiral aromatic aldimines, in which differentially substituted alkenes are tethered meta to the imine, was investigated. High enantioselectivities were obtained for imines prepared from aminoindane derivatives, which function as directing groups for the rhodium-catalyzed C-H bond activation. Initial demonstration of catalytic asymmetric intramolecular alkylation also was achieved by employing a sterically hindered achiral imine substrate and catalytic amounts of a chiral amine.

  6. Ruthenium-catalyzed direct C3 alkylation of indoles with α,β-unsaturated ketones.

    PubMed

    Li, Shuai-Shuai; Lin, Hui; Zhang, Xiao-Mei; Dong, Lin

    2015-01-28

    In this paper, a simple and highly efficient ruthenium-catalyzed direct C3 alkylation of indoles with various α,β-unsaturated ketones without chelation assistance has been developed. This novel C-H activation methodology exhibits a broad substrate scope such as different substituted indoles, pyrroles, and other azoles. Further synthetic applications of the alkylation products can lead to more attractive 3,4-fused tricyclic indoles.

  7. Effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties.

    PubMed

    Dasgupta, Debarshi; Kendhale, Amol M; Debije, Michael G; Ter Schiphorst, Jeroen; Shishmanova, Ivelina K; Portale, Giuseppe; Schenning, Albertus P H J

    2014-08-01

    The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied. It was found that the dichroic properties of perylene bisimides in a liquid crystal host can be reversed with a single synthetic step by ortho alkylation. Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed. Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

  8. Investigating Hydrogen Bonding in Phenol Using Infrared Spectroscopy and Computational Chemistry

    ERIC Educational Resources Information Center

    Fedor, Anna M.; Toda, Megan J.

    2014-01-01

    The hydrogen bonding of phenol can be used as an introductory model for biological systems because of its structural similarities to tyrosine, a para-substituted phenol that is an amino acid essential to the synthesis of proteins. Phenol is able to form hydrogen bonds readily in solution, which makes it a suitable model for biological…

  9. Sterically Controlled Cu-Catalyzed or Transition-Metal-Free Cross-Coupling of gem-Difluoroalkenes with Tertiary, Secondary, and Primary Alkyl Grignard Reagents.

    PubMed

    Dai, Wenpeng; Shi, Hongyan; Zhao, Xianghu; Cao, Song

    2016-09-02

    A robust copper-catalyzed or transition-metal-free cross-coupling of gem-difluoroalkenes with tertiary, secondary, and primary alkyl Grignard reagents has been developed. Remarkably, the tertiary and secondary alkylation of gem-difluoroalkenes proceeded very smoothly in the presence of 25 mol % of CuCN or under transition-metal-free conditions, affording the tertiary and secondary alkyl-substituted fluoroalkenes in good to excellent yields with excellent Z stereoselectivity.

  10. Mild Catalytic methods for Alkyl-Alkyl Bond Formation

    SciTech Connect

    Vicic, David A

    2009-08-10

    Overview of Research Goals and Accomplishments for the Period 07/01/06 – 06/30/07: Our overall research goal is to transform the rapidly emerging synthetic chemistry involving alkyl-alkyl cross-couplings into more of a mechanism-based field so that that new, rationally-designed catalysts can be performed under energy efficient conditions. Our specific objectives for the previous year were 1) to obtain a proper electronic description of an active catalyst for alkyl-alkyl cross-coupling reactions and 2) to determine the effect of ligand structure on the rate, scope, selectivity, and functional group compatibility of C(sp3)-C(sp3) cross-coupling catalysis. We have completed both of these initial objectives and established a firm base for further studies. The specific significant achievements of the current grant period include: 1) we have performed magnetic and computational studies on (terpyridine)NiMe, an active catalyst for alkyl-alkyl cross couplings, and have discovered that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand; 2) we have for the first time shown that alkyl halide reduction by terpyridyl nickel catalysts is substantially ligand based; 3) we have shown by isotopic labeling studies that the active catalyst (terpyridine)NiMe is not produced via a mechanism that involves the formation of methyl radicals when (TMEDA)NiMe2 is used as the catalyst precursor; 4) we have performed an extensive ligand survey for the alkyl-alkyl cross-coupling reactions and have found that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors; 5) we have found that the use of bis(dialkylphosphino)methanes as ligands for nickel does not produce active catalysts for cross-coupling but rather leads to bridging hydride

  11. Microbial degradation of n-alkyl tetrahydrothiophenes found in petroleum.

    PubMed Central

    Fedorak, P M; Payzant, J D; Montgomery, D S; Westlake, D W

    1988-01-01

    Although n-alkyl-substituted tetrahydrothiophenes are found in nonbiodegraded petroleums, they are not found in petroleums which have undergone biodegradation in their reservoirs. These observations suggested that this group of compounds with alkyl chain lengths from approximately C10 to at least C30 is biodegradable. Two of these sulfides, 2-n-dodecyltetrahydrothiophene (DTHT) and 2-n-undecyltetrahydrothiophene, were synthesized, and their biodegradabilities were tested by using five gram-positive, n-alkane-degrading bacterial isolates. The alkyl side chains of these compounds were oxidized, and the major intermediates found in 2-n-undecyltetrahydrothiophene- and DTHT-metabolizing cultures were 2-tetrahydrothiophenecarboxylic acid (THTC) and 2-tetrahydrothiopheneacetic acid (THTA), respectively. Four n-alkane-degrading fungi were also shown to degrade DTHT, yielding both THTA and THTC. Quantitation of tetrahydrothiophene ring-containing products in 28-day-old bacterial and fungal cultures suggested that THTC and THTA were metabolized further to unidentified products. In addition, two of the bacterial isolates were shown to degrade a mixture of n-alkyl tetrahydrothiophenes isolated from Bellshill Lake crude oil. PMID:3389816

  12. Nickel-Catalyzed Allylic Alkylation with Diarylmethane Pronucleophiles: Reaction Development and Mechanistic Insights.

    PubMed

    Sha, Sheng-Chun; Jiang, Hui; Mao, Jianyou; Bellomo, Ana; Jeong, Soo A; Walsh, Patrick J

    2016-01-18

    Palladium-catalyzed allylic substitution reactions are among the most efficient methods to construct C-C bonds between sp(3)-hybridized carbon atoms. In contrast, much less work has been done with nickel catalysts, perhaps because of the different mechanisms of the allylic substitution reactions. Palladium catalysts generally undergo substitution by a "soft"-nucleophile pathway, wherein the nucleophile attacks the allyl group externally. Nickel catalysts are usually paired with "hard" nucleophiles, which attack the metal before C-C bond formation. Introduced herein is a rare nickel-based catalyst which promotes substitution with diarylmethane pronucleophiles by the soft-nucleophile pathway. Preliminary studies on the asymmetric allylic alkylation are promising.

  13. Syntheses and analytical characterizations of N-alkyl-arylcyclohexylamines.

    PubMed

    Wallach, Jason; Colestock, Tristan; Cicali, Brian; Elliott, Simon P; Kavanagh, Pierce V; Adejare, Adeboye; Dempster, Nicola M; Brandt, Simon D

    2016-08-01

    The rise in new psychoactive substances that are available as 'research chemicals' (RCs) remains a significant forensic and legislative challenge. A number of arylcyclohexylamines have attracted attention as RCs and continue to be encountered, including 3-MeO-PCP, 3-MeO-PCE and 3-MeO-PCPr. These compounds are commonly perceived as ketamine-like dissociative substances and are believed to act predominantly via antagonism of the N-methyl-D-aspartate (NMDA) receptor. To aid in the identification of newly emerging substances of abuse, the current studies were performed. The syntheses of fifteen N-alkyl-arylcyclohexylamines are described. Analytical characterizations were performed via gas chromatography and high performance liquid chromatography coupled to multiple forms of mass spectrometry as well as nuclear magnetic resonance spectroscopy, ultraviolet diode array detection and infrared spectroscopy. The series consisted of the N-alkyl derivatives (N-methyl, N-ethyl, N-propyl) of phenyl-substituted and isomeric 2-, 3- and 4-methoxy phenylcyclohexylamines, as well as the N-alkyl derivatives obtained from 3-methylphenyl and 2-thienyl moieties. In addition to the presentation of a range of previously unreported data, it was also found that positional isomers of aryl methoxyl-substituted arylcyclohexylamines were readily distinguishable under a variety of analytical conditions. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Domino cyclization-alkylation protocol for the synthesis of 2,3-functionalized indoles from o-alkynylanilines and allylic alcohols.

    PubMed

    Xu, Chang; Murugan, Vinod K; Pullarkat, Sumod A

    2012-05-21

    A practical and efficient protocol for the one-pot synthesis of 2,3-substituted indoles was developed via a palladacycle catalyzed domino cyclization-alkylation reaction involving 2-alkynylanilines and allylic alcohols under mild conditions without any additives.

  15. Asymmetric Friedel-Crafts alkylations of indoles with dialkyl 3-oxoprop-1-enylphosphonates: organocatalytic enantioselective synthesis of alpha-indolyl phosphonates.

    PubMed

    Guo, Ying-Cen; Li, Dong-Ping; Li, Yu-Ling; Wang, Hong-Mei; Xiao, Wen-Jing

    2009-08-01

    Organocatalytic enantioselective synthesis of alpha-indolyl phosphonates has been successfully carried out via asymmetric Friedel-Crafts alkylation of substituted indoles with (E)-dialkyl 3-oxoprop-1-enylphosphonates in 48-82% yield and 73-96% ee.

  16. The Phenol-Ene Reaction: Biaryl Synthesis via Trapping Reactions between HDDA-Generated Benzynes and Phenolics.

    PubMed

    Zhang, Juntian; Niu, Dawen; Brinker, Vincent A; Hoye, Thomas R

    2016-11-04

    Benzynes produced thermally by the cycloisomerization of triyne-containing precursors [i.e., by the hexadehydro-Diels-Alder (HDDA) reaction] react with phenols at the carbon ortho to the hydroxyl in an enelike fashion. Following tautomerization of the intermediate cyclohexadienones, this produces biaryl derivatives. DFT calculations of model reactions support this mechanistic interpretation. Substituted, unsymmetrical phenols and bis-phenols react in a fashion that can be explained by engagement of the most readily available (non-hydrogen-bonded) hydroxyl in the phenol-ene process.

  17. Regio- and Stereoselective Modification of Chiral α-Amino Ketones by Pd-Catalyzed Allylic Alkylation.

    PubMed

    Huwig, Kai; Schultz, Katharina; Kazmaier, Uli

    2015-07-27

    Chiral α-amino ketones are excellent nucleophiles for stereoselective palladium-catalyzed allylic alkylations. Both chiral as well as achiral allylic substrates can be applied, while the stereochemical outcome of the reaction is controlled by the chiral ketone enolate. The substituted amino ketones formed can be reduced stereoselectively, and up to five consecutive stereogenic centers can be obtained. This approach can be used for the synthesis of highly substituted piperidine derivatives.

  18. Copper-Catalyzed Alkylation of Nitroalkanes with α-Bromonitriles: Synthesis of β-Cyanonitroalkanes.

    PubMed

    Shimkin, Kirk W; Gildner, Peter G; Watson, Donald A

    2016-03-04

    Copper catalysis now enables the efficient C-alkylation of nitroalkanes with α-bromonitriles. Using a simple and inexpensive catalyst, this process provides access to β-cyanonitroalkanes. The method is highly tolerant of various functional groups and substitution patterns. These functionally dense products serve as orthogonally masked 1,3-diamines, which can be revealed selectively for access to differentially substituted diamines. These products can also be exploited for the formation of complex cyanoalkenes and 5-aminoisoxazoles.

  19. Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

    PubMed

    Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

    2015-01-02

    A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines.

  20. Natural and bioremediated selective degradation of polycyclic aromatic alkyl isomers in oil-contaminated soils

    SciTech Connect

    Sauer, T.C.; McCarthy, K.; Uhler, A.; Porta, A.

    1995-12-31

    In studies where 2- to 6-ring polycyclic aromatic hydrocarbons (PAHs) are determined as part of characterizing released oil constituents in environmental samples, the changes in composition of PAHs from weathering (e.g., evaporation, dissolution) and biodegradation are most often represented by PAH alkyl homologue distributions. Concentrations of PAH alkyl groups are the sum of individual PAH isomers of similar carbon number; such as for C2-naphthalenes, the C2 alkyl group consists of dimethyl and ethyl substitutions on the parent naphthalene. In weathering and degradation studies, the changes in relative concentration of the individual isomers within an alkyl group are rarely reported. In a field study of oiled soils, the authors looked at the selective losses, for a period of a year, of individual PAH alkyl isomers that occur both naturally by weathering processes and through the use of bioremediation technology. Results showed that decreases in alkyl group concentrations were not always represented by similar losses of each isomer in the alkyl group, but were often due to the preferential or selective loss of certain isomers in the group.

  1. Synthesis, characterization and reactivity of heteroleptic rare earth metal bis(phenolate) complexes.

    PubMed

    Qi, Ruipeng; Liu, Bao; Xu, Xiaoping; Yang, Zijian; Yao, Yingming; Zhang, Yong; Shen, Qi

    2008-10-07

    The synthesis, characterization and reactivity of heteroleptic rare earth metal complexes supported by the carbon-bridged bis(phenolate) ligand 2,2'-methylene-bis(6-tert-butyl-4-methyl-phenoxo) (MBMP2-) are described. Reaction of (C5H5)3Ln(THF) with MBMPH2 in a 1:1.5 molar ratio in THF at 50 degrees C produced the heteroleptic rare earth metal bis(phenolate) complexes (C5H5)Ln(MBMP)(THF)n (Ln=La, n=3 (); Ln=Yb (), Y (), n=2) in nearly quantitative yields. The residual C5H5- groups in complexes to can be substituted by the bridged bis(phenolate) ligands at elevated temperature to give the neutral rare earth metal bis(phenolate) complexes, and the ionic radii have a profound effect on the structures of the final products. Complex reacted with MBMPH2 in a 1:0.5 molar ratio in toluene at 80 degrees C to produce a dinuclear complex (MBMP)La(THF)(micro-MBMP)2La(THF)2 () in good isolated yield; whereas complexes and reacted with MBMPH2 under the same conditions to give (MBMP)Ln(MBMPH)(THF)2 (Ln=Yb (), Y ()) as the final products, in which one hydroxyl group of the phenol is coordinated to the rare earth metal in a neutral fashion. The reactivity of complexes and with some metal alkyls was explored. Reaction of complex with 1 equiv. of AlEt3 in toluene at room temperature afforded unexpected ligand redistributed products, and a discrete ion pair ytterbium complex [(MBMP)Yb(THF)2(DME)][(MBMP)2Yb(THF)2] () was isolated in moderate yield. Furthermore, reaction of complex with 1 equiv. of ZnEt2 in toluene gave a ligand redistributed complex [(micro-MBMP)Zn(THF)]2 () in reasonable isolated yield. Similar reaction of complex with ZnEt2 also afforded complex ; whereas the reaction of complex with 1 equiv. of n-BuLi in THF afforded the heterodimetallic complex [(THF)Yb(MBMP)2Li(THF)2] (). All of these complexes were well characterized by elemental analyses, IR spectra, and single-crystal structure determination, in the cases of complexes , and -.

  2. Combustion Pathways of the Alkylated Heteroaromatics: Bond Dissociation Enthalpies and Alkyl Group Fragmentations

    NASA Astrophysics Data System (ADS)

    Hayes, Carrigan J.; Hadad, Christopher M.

    2009-04-01

    The bond dissociation enthalpies (BDEs) of the alkyl groups of the alkyl-substituted heterocycles have been studied and compiled using DFT methodology, with the intent of modeling the larger heterocyclic functionalities found in coal. DFT results were calibrated against CBS-QB3 calculations, and qualitative trends were reproduced between these methods. Loss of hydrogen at the benzylic position provided the most favorable route to radical formation, for both the azabenzenes and five-membered heterocycles. The ethyl derivatives had lower BDE values than the methyl derivatives due to increased stabilization of the corresponding radicals. Calculated spin densities correlated well with bond dissociation enthalpies for these compounds, while geometric effects were minimal with respect to the heterocycles themselves. Temperature effects on the bond dissociation enthalpies were minor, ranging by about 5 kcal/mol from 298 to 2000 K; the free energies of reaction dropped significantly over the same range due to entropic effects. Monocyclic heteroaromatic rings were seen to replicate the chemistry of multicyclic heteroaromatic systems.

  3. Outlook for the U. S. alkylation industry

    SciTech Connect

    Felten, J.R.; Bradshaw, T.; McCarthy, K. )

    1994-01-01

    Alkylation has long been recognized in the refining industry as one of the best options to convert refinery olefins into valuable, clean, high octane blending components. In fact, refinery alkylation is a preferred source of blending stocks for reformulated gasoline. However, the hydrofluoric acid (HF) alkylation process and, to a lesser extent, the sulfuric acid (SA) process have come under increasing pressure in the US due to safety and environmental concerns. This paper examines the current outlook for the US alkylation industry including: key trends and driving forces in the industry, the impact of environmental issues on both HF and SA alkylation, US alkylation supply/demand forecast including the outlook for oxygenates, how US refines will respond to the increased demand and restricted supply for alkylates, and the outlook for new solid acid alkylation (SAC) technology.

  4. Total synthesis of alkyl citrate natural products.

    PubMed

    Rizzacasa, Mark A; Sturgess, Dayna

    2014-03-07

    This review highlights the synthesis of members of the alkyl citrate family of natural products. The focus is on the stereoselective construction of the alkyl citrate moiety common to these compounds.

  5. Direct C-H alkylation and indole formation of anilines with diazo compounds under rhodium catalysis.

    PubMed

    Mishra, Neeraj Kumar; Choi, Miji; Jo, Hyeim; Oh, Yongguk; Sharma, Satyasheel; Han, Sang Hoon; Jeong, Taejoo; Han, Sangil; Lee, Seok-Yong; Kim, In Su

    2015-12-18

    The rhodium(III)-catalyzed direct functionalization of aniline C-H bonds with α-diazo compounds is described. These transformations provide a facile construction of ortho-alkylated anilines with diazo malonates or highly substituted indoles with diazo acetoacetates.

  6. Alkyl substituent effects on gas-phase acidities - The influence of hybridization.

    NASA Technical Reports Server (NTRS)

    Brauman, J. I.; Blair, L. K.

    1971-01-01

    Exploration of the effect on acidity of alkyl groups bonded to trigonal and digonal carbon. Some results on the relative acidities of toluene and p-xylene, and acetylene and substitute acetylenes, as determined by ion cyclotron resonance (icr) spectroscopy, are described. Some limitations of the CNDO/2 calculation method are discussed.

  7. Removal of phenols from wastewater by soluble and immobilized tyrosinase

    SciTech Connect

    Wada, Shinji; Ichikawa, Hiroyasu; Tatsumi, Kenji )

    1993-09-20

    An enzymatic method for removal of phenols from industrial wastewater was investigated. Phenols in an aqueous solution were removed after treatment with mushroom tyrosinase. The reduction order of substituted phenols is catechol > p-cresol > p-chlorophenol > phenol > p-methoxyphenol. In the treatment of tyrosinase alone, no precipitate was formed but a color change from colorless to dark-brown was observed. The colored products were removed by chitin and chitosan which are available abundantly as shellfish waste. In addition, the reduction rate of phenols was observed to be accelerated in the presence of chitosan. Tyrosinase, immobilized by using amino groups in the enzyme on cation exchange resins, can be used repeatedly. By treatment with immobilized tyrosinase, 100% of phenol was removed after 2 h, and the activity was reduced very little even after 10 repeat treatments.

  8. Chichibabin-type direct alkylation of pyridyl alcohols with alkyl lithium reagents.

    PubMed

    Jeffrey, Jenna L; Sarpong, Richmond

    2012-11-02

    Direct C(6) alkylation of pyridyl alcohols can be achieved following an initial deprotonation of the hydroxy group. This transformation, which is believed to occur by a Chichibabin-type alkylation, avoids lateral deprotonation prior to pyridine ring alkylation and gives increased regioselectivity for C(6) over C(4) alkylation.

  9. Refiners discuss HF alkylation process and issues

    SciTech Connect

    Not Available

    1992-04-06

    Safety and oxygenate operations made HF alkylation a hot topic of discussion at the most recent National Petroleum Refiners Association annual question and answer session on refining and petrochemical technology. This paper provides answers to a variety of questions regarding the mechanical, process, and safety aspects of the HF alkylation process. Among the issues discussed were mitigation techniques, removal of oxygenates from alkylation unit feed, and amylene alkylation.

  10. Pyrolysis of phenolic impregnated carbon ablator (PICA).

    PubMed

    Bessire, Brody K; Lahankar, Sridhar A; Minton, Timothy K

    2015-01-28

    Molar yields of the pyrolysis products of thermal protection systems (TPSs) are needed in order to improve high fidelity material response models. The volatile chemical species evolved during the pyrolysis of a TPS composite, phenolic impregnated carbon ablator (PICA), have been probed in situ by mass spectrometry in the temperature range 100 to 935 °C. The relative molar yields of the desorbing species as a function of temperature were derived by fitting the mass spectra, and the observed trends are interpreted in light of the results of earlier mechanistic studies on the pyrolysis of phenolic resins. The temperature-dependent product evolution was consistent with earlier descriptions of three stages of pyrolysis, with each stage corresponding to a temperature range. The two main products observed were H2O and CO, with their maximum yields occurring at ∼350 °C and ∼450 °C, respectively. Other significant products were CH4, CO2, and phenol and its methylated derivatives; these products tended to desorb concurrently with H2O and CO, over the range from about 200 to 600 °C. H2 is presumed to be the main product, especially at the highest pyrolysis temperatures used, but the relative molar yield of H2 was not quantified. The observation of a much higher yield of CO than CH4 suggests the presence of significant hydroxyl group substitution on phenol prior to the synthesis of the phenolic resin used in PICA. The detection of CH4 in combination with the methylated derivatives of phenol suggests that the phenol also has some degree of methyl substitution. The methodology developed is suitable for real-time measurements of PICA pyrolysis and should lend itself well to the validation of nonequilibrium models whose aim is to simulate the response of TPS materials during atmospheric entry of spacecraft.

  11. 40 CFR 721.9892 - Alkylated urea.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under...

  12. One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

    PubMed Central

    Peshkov, Roman Yu; Chunyan, Wang; Tretyakov, Evgeny V; Shteingarts, Vitalij D

    2016-01-01

    Summary A convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups, fluorine atoms, and a 1-cyanonaphthalene residue. The variety of ω-substituted alkyl bromides, including an extra bromine atom, a double bond, cyano and ester groups, as well as a 1,3-dioxane fragment are suitable as alkylation reagents. PMID:27559409

  13. Palladium-catalyzed regioselective carbonylation of C-H bonds of N-alkyl anilines for synthesis of isatoic anhydrides.

    PubMed

    Guan, Zheng-Hui; Chen, Ming; Ren, Zhi-Hui

    2012-10-24

    A Pd-catalyzed regioselective C-H bond carbonylation of N-alkyl anilines for the synthesis of isatoic anhydrides has been developed. The key Pd-catalyst intermediate has been isolated and characterized. This novel Pd-catalyzed carbonylation reaction tolerates a wide range of functional groups and is a reliable method for the rapid elaboration of readily available N-alkyl anilines into a variety of substituted isatoic anhydrides under mild conditions.

  14. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium from a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant to and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate, nonsaturated in uranium. The uranium is stripped from, the organic extractant into the stripping solution, and the resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  15. Process for recovering uranium using an alkyl pyrophosphoric acid and alkaline stripping solution

    SciTech Connect

    Worthington, R.E.; Magdics, A.

    1987-03-24

    A process is described for stripping uranium for a pregnant organic extractant comprising an alkyl pyrophosphoric acid dissolved in a substantially water-immiscible organic diluent. The organic extractant contains tetravalent uranium and an alcohol or phenol modifier in a quantity sufficient to retain substantially all the unhydrolyzed alkyl pyrophosphoric acid in solution in the diluent during stripping. The process comprises adding an oxidizing agent to the organic extractant and thereby oxidizing the tetravalent uranium to the +6 state in the organic extractant, and contacting the organic extractant containing the uranium in the +6 state with a stripping solution comprising an aqueous solution of an alkali metal or ammonium carbonate or hydroxide thereby stripping uranium from the organic extractant into the stripping solution. The resulting barren organic extractant containing substantially all of the unhydrolyzed alkyl pyrophosphoric acid dissolved in the diluent is separated from the stripping solution containing the stripped uranium, the barren extractant being suitable for recycle.

  16. Phenol removal pretreatment process

    DOEpatents

    Hames, Bonnie R.

    2004-04-13

    A process for removing phenols from an aqueous solution is provided, which comprises the steps of contacting a mixture comprising the solution and a metal oxide, forming a phenol metal oxide complex, and removing the complex from the mixture.

  17. Detection of phenols using engineered bacteria

    DOEpatents

    Wise, Arlene A.; Kuske, Cheryl R.; Terwilliger, Thomas C.

    2007-12-04

    Detection of phenols using engineered bacteria. A biosensor can be created by placing a reporter gene under control of an inducible promoter. The reporter gene produces a signal when a cognate transcriptional activator senses the inducing chemical. Creation of bacterial biosensors is currently restricted by limited knowledge of the genetic systems of bacteria that catabolize xenobiotics. By using mutagenic PCR to change the chemical specificity of the Pseudomonas species CF600 DmpR protein, the potential for engineering novel biosensors for detection of phenols has been demonstrated. DmpR, a well-characterized transcriptional activator of the P. CF600's dmp operon mediates growth on simple phenols. Transcription from Po, the promoter heading the dmp operon, is activated when the sensor domain of DmpR interacts with phenol and mono-substituted phenols. By altering the sensor domain of the DmpR, a group of DmpR derivatives that activate transcription of a Po-lacZ fusion in response to eight of the EPA's eleven priority pollutant phenols has been created. The assays and the sensor domain mutations that alter the chemical specificity of DmpR is described.

  18. Detection of phenols using engineered bacteria

    DOEpatents

    Wise, Arlene A.; Kuske, Cheryl R.; Terwilliger, Thomas C.

    2004-08-10

    Detection of phenols using engineered bacteria. A biosensor can be created by placing a reporter gene under control of an inducible promoter. The reporter gene produces a signal when a cognate transcriptional activator senses the inducing chemical. Creation of bacterial biosensors is currently restricted by limited knowledge of the genetic systems of bacteria that catabolize xenobiotics. By using mutagenic PCR to change the chemical specificity of the Pseudomonas species CF600 DmpR protein, the potential for engineering novel biosensors for detection of phenols has been demonstrated. DmpR, a well-characterized transcriptional activator of the P. CF600's dmp operon mediates growth on simple phenols. Transcription from Po, the promoter heading the dmp operon, is activated when the sensor domain of DmpR interacts with phenol and mono-substituted phenols. By altering the sensor domain of the DmpR, a group of DmpR derivatives that activate transcription of a Po-lacZ fusion in response to eight of the EPA's eleven priority pollutant phenols has been created. The assays and the sensor domain mutations that alter the chemical specificity of DmpR is described.

  19. [Efficient synthesis of multisubstituted aromatic compounds from phenol derivatives].

    PubMed

    Ikawa, Takashi

    2014-01-01

    Phenols are abundant in nature and diverse phenols are readily available commercially at low cost. Thus, phenols can be used as the raw materials for the synthesis of valuable multisubstituted aromatic compounds by the direct activation of phenolic hydroxyl groups (C-O bond activation), followed by substitutions with other substituents. Although the derivatization of phenolic hydroxyl groups to sulfonates, such as triflates, nonaflates, tosylates and mesylates, followed by the transition-metal-catalyzed coupling reactions has been extensively investigated for this purpose, the direct C-O bond activation of phenols for subsequent functional group transformation has been a long-standing challenge in modern organic synthesis. In this review, I have summarized my recent studies on the formal direct C-O bond activation of phenols using nonafluorobutanesulfonyl fluoride (NfF) for the synthesis of multisubstituted aromatics. I have focused on the dual use of NfF, a less expensive commercially available reagent, including the tentative formation of highly reactive nonaflates from phenols and the use of the liberated fluoride ion as a nucleophile to promote the reactions of nonaflates. The following four topics are discussed: 1) palladium-catalyzed coupling reactions of phenols, 2) novel preparation of benzynes from 2-silylphenols, 3) synthesis of fluorinated aromatic compounds via the formation of benzynes, and 4) Hiyama coupling of (tert-butyldimethylsilyl)arenes activated by internal phenolic hydroxyl groups.

  20. Synthesis and biological studies of N-alkylated cyclic diamines.

    PubMed

    Xiong, Xiao-Qin; Liang, Feng; Yang, Li; Zhou, Xiang; Zheng, Cong-Yi; Cao, Xiao-Ping

    2007-01-01

    Several alkyl-substituted mesocyclic diamines were synthesized, and their interaction with DNA were studied by melting-temperature measurements and the ethidium bromide (EB)-fluorescence competitive method. The supercoiled DNA hydrolytic cleavage by 1,4-dioctyl-1,4-diazepan-6-ol (4) was supported by the evidence from free-radical quenching and T4-ligase ligation. Preliminary pharmacological tests showed that only 1,4-dioctyl-1,4-diazepan-6-ol (4) had antitumor activity against HeLa cell lines in vitro.

  1. Hydroprocessing of substituted benzenes over a sulfided CoO-MoO sub 3 /. gamma. -Al sub 2 O sub 3 catalyst

    SciTech Connect

    Moreau, C.; Joffre, J.; Saenz, C.; Geneste, P. )

    1990-04-01

    The literature data concerning the hydroprocessing of substituted benzenes show that CoMo/Al{sub 2}O{sub 3} and NiMo/Al{sub 2}O{sub 3} catalysts behave differently. For example, the hydrodeoxygenation of methyl-substituted phenols proceeds mainly through hydrogenolysis of the C-O bond over a sulfided CoMo/Al{sub 2}O{sub 3} catalyst and the authors concerned have also proposed that different active sites were responsible for the two reaction paths, one for C-O bond cleavage and another for hydrogenation. Over a sulfided NiMo/Al{sub 2}O{sub 3} catalyst, the authors have shown that the hydrodeoxygenation of phenols substituted by alkyl, cycloalkyl, or phenyl groups occurs mostly through ring hydrogenation. From a recent compilation of results obtained under similar operating conditions in their laboratory for numerous model compounds and those reported in the literature, the authors arrived at the conclusion that the difference between NiMo/Al{sub 2}O{sub 3} and CoMo/Al{sub 2}O{sub 3} catalysts lies in the hydrogenolysis rather than in the hydrogenation properties. It was thus interesting to consider the behavior of a CoMo/Al{sub 2}O{sub 3} catalyst toward a series of X-substituted benzenes as was done with the NiMo/Al{sub 2}O{sub 3} catalyst. This could provide further information concerning the interactions between the catalyst and the organic molecules, the nature of the catalytic sites, and the mechanism of hydrogenation and hydrogenolysis reactions.

  2. Methods of making alkyl esters

    DOEpatents

    Elliott, Brian

    2010-08-03

    A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.

  3. Stereoselective umpolung tandem addition of heteroatoms to phenol.

    PubMed

    Todd, Michael A; Sabat, Michal; Myers, William H; Smith, Timothy M; Harman, W Dean

    2008-06-04

    Upon coordination to {TpW(PMe3)(NO)}, phenol tautomerizes to a cyclohexadienone (a 2H-phenol). The uncoordinated, nonaromatic double bond of this ligand undergoes stepwise addition of electrophiles followed by nucleophiles to produce 4,5-disubstituted cyclohexenone complexes. The metal stabilizes the intermediate cationic ligand and sterically blocks one face of the ligand, resulting in a high degree of stereo- and regiocontrol. These substituted cyclohexenones are readily liberated from the metal by oxidative decomplexation.

  4. PREPARATION OF ALKYL PYROPHOSPHATE EXTRACTANTS

    DOEpatents

    Levine, C.A.; Skiens, W.E.; Moore, G.R.

    1960-08-01

    A process for providing superior solvent extractants for metal recovery processes is given wherein the extractant comprises an alkyl pyrophosphoric acid ester dissolved in an organic solvent diluent. Finely divided solid P/sub 2/O/ sub 5/ is slurried in an organic solvent-diluent selected from organic solvents such as kerosene, benzene, chlorobenzene, toluene, etc. An alcohol selected from the higher alcohols having 4 to 17 carbon atoms. e.g.. hexanol-1. heptanol-3, octanol-1. 2.6-dimethyl-heptanol-4, and decanol-1, is rapidly added to the P/sub 2/O/sub 5/ slurry in the amount of about 2 moles of alcohol to 1 mole of P/sub 2/ O/sub 5/. The temperature is maintained below about 110 deg C during the course of the P/sub 2/O/sub 5/-alcohol reaction. An alkyl pyrophosphate extractant compound is formed as a consequence of the reaction process. The alkyl pyrophosphate solvent-diluent extractant phase is useful in solvent extraction metal recovery processes.

  5. Iron-Catalyzed Decarboxylative Alkyl Etherification of Vinylarenes with Aliphatic Acids as the Alkyl Source.

    PubMed

    Jian, Wujun; Ge, Liang; Jiao, Yihang; Qian, Bo; Bao, Hongli

    2017-03-20

    Because of the lack of effective alkylating reagents, alkyl etherification of olefins with general alkyl groups has not been previously reported. In this work, a variety of alkyl diacyl peroxides and peresters generated from aliphatic acids have been found to enable the first iron-catalyzed alkyl etherification of olefins with general alkyl groups. Primary, secondary and tertiary aliphatic acids are suitable for this reaction, delivering products with yields up to 97 %. Primary and secondary alcohols react well, affording products in up to 91 % yield.

  6. Highly efficient synthesis of phenols by copper-catalyzed hydroxylation of aryl iodides, bromides, and chlorides.

    PubMed

    Yang, Kai; Li, Zheng; Wang, Zhaoyang; Yao, Zhiyi; Jiang, Sheng

    2011-08-19

    8-Hydroxyquinolin-N-oxide was found to be a very efficient ligand for the copper-catalyzed hydroxylation of aryl iodides, aryl bromides, or aryl chlorides under mild reaction conditions. This methodology provides a direct transformation of aryl halides to phenols and to alkyl aryl ethers. The inexpensive catalytic system showed great functional group tolerance and excellent selectivity.

  7. Water extracts of tree Hypericum sps. protect DNA from oxidative and alkylating damage and enhance DNA repair in colon cells.

    PubMed

    Ramos, Alice A; Marques, Filipe; Fernandes-Ferreira, Manuel; Pereira-Wilson, Cristina

    2013-01-01

    Diet may induce colon carcinogenesis through oxidative or alkylating DNA damage. However, diet may also contain anticarcinogenic compounds that contribute to cancer prevention. DNA damage prevention and/or induction of repair are two important mechanisms involved in cancer chemoprevention by dietary compounds. Hypericum sps. are widely used in traditional medicine to prepare infusions due to their beneficial digestive and neurologic effects. In this study, we investigated the potential of water extracts from three Hypericum sps. and some of their main phenolic compounds to prevent and repair oxidative and alkylating DNA damage in colon cells. The results showed that water extracts of Hypericum perforatum, Hypericum androsaemum, Hypericum undulatum, quercetin and rutin have protective effect against oxidative DNA damage in HT29 cells. Protective effect was also observed against alkylating DNA damage induced by methyl-methanesulfonate, except for H. androsaemum. With regard to alkylating damage repair H. perforatum, H. androsaemum and chlorogenic acid increased repair of alkylating DNA damage by base excision repair pathway. No effect was observed on nucleotide excision repair pathway. Antigenotoxic effects of Hypericum sps. may contribute to colon cancer prevention and the high amount of phenolic compounds present in Hypericum sps. play an important role in DNA protective effects.

  8. Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions.

    PubMed

    Breitenfeld, Jan; Ruiz, Jesus; Wodrich, Matthew D; Hu, Xile

    2013-08-14

    Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the oxidative addition of alkyl halide. The catalysis is second-order in Grignard reagent, first-order in catalyst, and zero-order in alkyl halide. A transient species, [(N2N)Ni-alkyl(2)](alkyl(2)-MgCl), is identified as the key intermediate responsible for the activation of alkyl halide, the formation of which is the turnover-determining step of the catalysis.

  9. Reactions of Tributylstannyl Anioniods with Alkyl Bromides.

    DTIC Science & Technology

    1981-09-28

    g (12 mmol) of cesium tert-butoxide was added to the reaction vessel before the addition of n-butyllithium. Alkylation of Tributylstannyl Anionoids...Dry reaction vessels were purged with argon. The desired alkyl halide (1.0 mmol unless noted) and any desired additive were added to the reaction ...OFFICE OF NAVAL RESEARCH Contract N00014-79-C-0584 Task No. NR 053-714 TECHNICAL REPORT No. 2 Reactions of Tributylstannyl Anionoids with Alkyl

  10. Carboxy, carboalkoxy and carbamile substituted isonitrile radionuclide complexes

    DOEpatents

    Jones, Alun G.; Davison, Alan; Kronauge, James; Abrams, Michael J.

    1989-01-01

    A coordination complex comprising a radionuclide selected from the class consisting of radioactive isotopes of Tc, Ru, Co, Pt and Re and an isonitrile ligand of the formula: (CNX)R, where X is a lower alkyl group having 1 to 4 carbon atoms, wherein R is selected from the group consisting of COOR.sup.1 and CONR.sup.2 R.sup.3 where R.sup.1 can be H, a pharmaceutically acceptable cation, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. R.sup.2, and R.sup.3 can be H, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and R.sup.2 and R.sup.3 can be the same of different is disclosed. Kits that can be used to form these complexes are also disclosed.

  11. Carboxy, carboalkoxy and carbamile substituted isonitrile radionuclide complexes

    DOEpatents

    Jones, Alun G.; Davison, Alan; Kronauge, James; Abrams, Michael J.

    1988-04-05

    A coordination complex comprising a radionuclide selected from the class consisting of radioactive isotopes of Tc, Ru, Co, Pt and Re and an isonitrile ligand of the formula: (CNX)R, where X is a lower alkyl group having 1 to 4 carbon atoms, wherein R is selected from the group consisting of COOR.sup.1 and CONR.sup.2 R.sup.3 where R.sup.1 can be H, a pharmaceutically acceptable cation, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R.sup.2, and R.sup.3 can be H, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and R.sup.2 and R.sup.3 can be the same or different is disclosed. Kits that can be used to form these complexes are also disclosed.

  12. Solvent substitution

    SciTech Connect

    Not Available

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  13. Phenol esterase activity of porcine skin.

    PubMed

    Laszlo, Joseph A; Smith, Leslie J; Evans, Kervin O; Compton, David L

    2015-01-01

    The alkyl esters of plant-derived phenols may serve as slow-release sources for cutaneous delivery of antioxidants. The ability of skin esterases to hydrolyze phenolic esters was examined. Esters of tyrosol and hydroxytyrosol were prepared from decanoic and lipoic acids. Ferulic acid was esterified with octadecanol, glycerol, and dioleoylglycerol. These phenolic derivatives were treated in taurodeoxycholate microemulsion and unilamellar liposomes with ex vivo porcine skin and an aqueous extract of the skin. Extracted esterases hydrolyzed the microemulsions at rates in the order: tyrosyl lipoate > tyrosyl decanoate > hydroxytyrosyl lipoate > hydroxytyrosyl decanoate. The tyrosyl decanoate was subject to comparatively little hydrolysis (10-30% after 24h) when incorporated into liposomes, while hydroxytyrosyl decanoate in liposomes was not hydrolyzed at all by the skin extract. Ferulate esters were not hydrolyzed by the extract in aqueous buffer, microemulsion, nor liposomes. Tyrosyl decanoate applied topically to skin explants in microemulsion were readily hydrolyzed within 4h, while hydrolysis was minimal when applied in liposomes. These findings indicate that porcine skin displays a general esterase activity toward medium-chain esters of tyrosol and hydroxytyrosol, which can be moderated by the physiochemical properties of the lipid vehicle, but no feruloyl esterase activity.

  14. Phenolic Wastewater Treatment Alternatives.

    DTIC Science & Technology

    1980-06-01

    pH 7 retention times become excessive. The manganese dioxide (Mn02 ) precipitates as a hydrous sludge which must be removed. This sludge becomes a...the sorptive properties of the hydrous MnO 2 often render it bene- ficial to clarification (Reference 22). On the other hand, it would increase the...SYSTEMS Phenol recovery systems are widely used for petroleum refi- nery wastes, coke-oven liquors , and phenol resin plant effluents, where waste phenol

  15. Probes for narcotic receptor mediated phenomena. 40.1 N-Substituted cis-4a-ethyl-1,2,3,4,4a,9a-hexahydrobenzofuro[2,3-c]pyridin-8-ols

    PubMed Central

    Iyer, Malliga R.; Lee, Yong Sok; Deschamps, Jeffrey R.; Rothman, Richard B.; Dersch, Christina M.; Jacobson, Arthur E.; Rice, Kenner C.

    2009-01-01

    A series of N-substituted rac-cis-4a-ethyl-1,2,3,4,4a,9a-hexahydrobenzofuro[2,3-c]pyridin-8-ols have been prepared using a simple synthetic route previously designed for synthesis of related cis-2-methyl-4a-alkyl-1,2,3,4,4a,9a-hexahydrobenzofuro[2,3-c]pyridin-6-ols. The new phenolic compounds, where the aromatic hydroxy moiety is situated ortho to the oxygen atom in the oxide-bridged ring, do not interact as well as the pyridin-6-ols with opioid receptors. The N-para-fluorophenethyl derivative had the highest μ-opioid receptor affinity of the examined compounds (Ki = 0.35 μM). PMID:20005115

  16. Acid-catalyzed ortho-alkylation of anilines with styrenes: an improved route to chiral anilines with bulky substituents.

    PubMed

    Cherian, Anna E; Domski, Gregory J; Rose, Jeffrey M; Lobkovsky, Emil B; Coates, Geoffrey W

    2005-11-10

    [reaction: see text] Reaction of para-substituted anilines with styrene derivatives at elevated temperatures, when catalyzed by CF3SO3H, results in highly chemoselective ortho-alkylation of the aniline. When R = H, dialkylation can be achieved by varying the ratio of styrene to aniline. Several different substituted anilines and styrenes were examined, and good yields (42-87%) were obtained, except in the case where electron-withdrawing substituents are present on the styrene.

  17. S-alkylation of soft scorpionates.

    PubMed

    Rajasekharan-Nair, Rajeev; Moore, Dean; Chalmers, Kirsten; Wallace, Dawn; Diamond, Louise M; Darby, Lisa; Armstrong, David R; Reglinski, John; Spicer, Mark D

    2013-02-11

    The alkylation reactions of soft scorpionates are reported. The hydrotris(S-alkyl-methimazolyl)borate dications (alkyl = methyl, allyl, benzyl), which were prepared by the reaction of Tm(Me) anion and primary alkyl halides, have been isolated and structurally characterised. The reaction is, however, not universally successful. DFT analysis of these alkylation reactions (C=S versus B-H alkylation) indicates that the observed outcome is driven by kinetic factors. Extending the study to incorporate alternative imine thiones (mercaptobenzothiazole, bz; thiazoline, tz) led to the structural characterisation of di[aquo-μ-aquohydrotris(mercaptobenzothiazolyl)boratosodium], which contains sodium atoms in the κ(3)-S,S,S coordination mode. Alkylation of Na[Tbz] and Na[tzTtz] leads to decomposition resulting in the formation of the simple S-alkylated heterocycles. The analysis of the species involved in these reactions shows an inherent weakness in the B-N bond in soft scorpionates, which has implications for their use in more advanced chemistry.

  18. Occupational asthma due to alkyl cyanoacrylate

    SciTech Connect

    Nakazawa, T. )

    1990-08-01

    A case of bronchial asthma induced by occupational exposure to alkyl cyanoacrylate, an adhesive, occurred in an assembly operation. Provocative exposure testing induced immediate and delayed asthmatic responses. Alkyl cyanoacrylate seemed to act as an allergen or as an irritant, resulting in the development of asthma.

  19. Phenolic Molding Compounds

    NASA Astrophysics Data System (ADS)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  20. Sulfonic acid resin-catalyzed addition of phenols, carboxylic acids, and water to olefins: Model reactions for catalytic upgrading of bio-oil.

    PubMed

    Zhang, Zhi-Jun; Wang, Qing-Wen; Yang, Xu-Lai; Chatterjee, Sabornie; Pittman, Charles U

    2010-05-01

    Acid-catalyzed 1-octene reactions with phenol and mixtures of phenol with water, acetic acid and 1-butanol were studied as partial bio-oil upgrading models. Bio-oil from fast biomass pyrolysis has poor fuel properties due to the presence of substantial amounts of water, carboxylic acid, phenolic derivatives and other hydroxyl-containing compounds. Additions across olefins offer a route to simultaneously lower water content and acidity while increasing hydrophobicity, stability and heating value. Amberlyst15, Dowex50WX2 and Dowex50WX4 effectively catalyzed phenol O- and C-alkylation from 65 to 120 degrees C, giving high O-alkylation selectivities in the presence of water, acetic acid and 1-butanol. Octanols and dioctyl ethers were formed from water and octyl acetates and phenol acetates from acetic acid. Phenol alkylation slowed in the presence of water. Dowex50WX2 and Dowex50WX4 were more stable in the presence of water than Amberlyst15 and were successfully recycled. Adding 1-butanol to phenol/water/1-octene, gave emulsion-like mixtures which improved phenol conversion and olefin hydration.

  1. Syntheses of L-tyrosine-related amino acids by tyrosine phenol-lyase of Citrobacter intermedius.

    PubMed

    Nagasawa, T; Utagawa, T; Goto, J; Kim, C J; Tani, Y; Kumagai, H; Yamada, H

    1981-06-01

    Degradation of tyrosine to phenol, pyruvate and ammonia by tyrosine phenol-lyase from Citrobacter intermedius (formerly named Escherichia intermedia) is readily reversible at high concentrations of pyruvate and ammonia. Spectrophotometric studies indicate that ammonia is the first substrate which interacts with bound pyridoxal 5'-phosphate. Kinetic results show that pyruvate is the second substrate bound, hence phenol must be the third. When an appropriate phenol derivative is substituted for phenol, the corresponding tyrosine analogue can be synthesized. 3-Fluoro-, 2-fluoro-, 3-chloro-, 2-chloro-, 3-bromo-, 2-bromo-, 2-iodo-, 3-methyl-, 2-methyl- and 2-methoxy-L-tyrosines have been synthesized by this reaction. By using various phenol derivatives or tyrosine analogues as substrates, the substrate specificity of tyrosine phenol-lyase is investigated and the situation of its active site is discussed.

  2. 5-(hydroxymethyl)oxazoles: versatile scaffolds for combinatorial solid-phase synthesis of 5-substituted oxazoles.

    PubMed

    Grabowska, U; Rizzo, A; Farnell, K; Quibell, M

    2000-01-01

    A scheme combining the preparation of building blocks in solution followed by solid-phase combinatorial chemistry has been developed to side-chain diversify 5-(hydroxymethyl)oxazole scaffold (1) into aryl ethers, thioethers, sulfones, sulfonamides, and carboxamides. Protected heterocyclic scaffolds 2 were linked to the solid phase and N-terminal derivatized using active ester chemistry, providing chemset 4¿1-4,1-4¿. The free side-chain hydroxyl of 4 was smoothly converted to aryl ethers 6 under Mitsunobu conditions, with a broad range of substituted phenols. Alternatively, quantitative conversion of hydroxyl to bromide followed by displacement with alkyl and aryl thiols gave thioethers 8. Thioethers were optionally oxidized to sulfones 9. Bromide displacement by azide, followed by reduction to amine and acylation with a range of carboxylic acids and sulfonyl chlorides gave carboxamides 11 and sulfonamides 13, respectively. Crude purity at typically >90% was observed for each of the five modifications detailed. A series of 20 compounds, exemplifying each modification, was reprepared, purified, and fully characterized.

  3. Chiral N,N'-Dioxide-Organocatalyzed Regio-, Diastereo- and Enantioselective Michael Addition-Alkylation Reaction.

    PubMed

    Feng, Juhua; Yuan, Xiao; Luo, Weiwei; Lin, Lili; Liu, Xiaohua; Feng, Xiaoming

    2016-10-24

    A highly regio-, diastereo- and enantioselective Michael addition-alkylation reaction between α-substituted cyano ketones and (Z)-bromonitrostyrenes has been realized by using a chiral N,N'-dioxide as organocatalyst. A variety of substrates performed well in this reaction, and the corresponding multifunctionalized chiral 2,3-dihydrofurans were obtained in up to 95 % yield with 95:5 dr and 93 % ee.

  4. Cyclic (Alkyl)(Amino)Carbene Complexes of Rhodium and Nickel and Their Steric and Electronic Parameters.

    PubMed

    Paul, Ursula S D; Sieck, Carolin; Haehnel, Martin; Hammond, Kai; Marder, Todd B; Radius, Udo

    2016-07-25

    N-heterocyclic carbenes (NHCs) and cyclic (alkyl)(amino)carbenes (CAACs) are of great interest, as their electronic and steric properties provide a unique class of ligands and organocatalysts. Herein, substitution reactions involving novel carbonyl complexes of rhodium and nickel were studied to provide a deeper understanding of the fundamental electronic factors characterizing CAAC(methyl) , which were compared with the large array of data available for NHC and sterically more demanding CAAC ligands.

  5. A highly enantioselective and regioselective organocatalytic direct Mannich reaction of methyl alkyl ketones with cyclic imines benzo[e][1,2,3]oxathiazine 2,2-dioxides.

    PubMed

    Wang, You-Qing; Cui, Xiao-Yu; Ren, Yuan-Yuan; Zhang, Yongna

    2014-12-07

    A highly enantioselective direct Mannich reaction of methyl alkyl ketones with cyclic imines benzo[e][1,2,3]oxathiazine 2,2-dioxides, catalyzed by the combination of cinchona alkaloid derived primary amine and TFA, is disclosed. For unsymmetrical methyl alkyl ketones, it is favoured that specific regioselective addition to the imine substrates occurs at the less-substituted methyl group by steric control.

  6. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.

    1989-07-18

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  7. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1994-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  8. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-09-07

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

  9. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1993-01-05

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  10. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.

    1989-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  11. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

  12. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1993-01-01

    Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

  13. Alkylation of organic aromatic compounds

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1994-06-14

    Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

  14. Elucidation of the ipso-Substitution Mechanism for Side-Chain Cleavage of α-Quaternary 4-Nonylphenols and 4-t-Butoxyphenol in Sphingobium xenophagum Bayram▿

    PubMed Central

    Gabriel, Frédéric L. P.; Cyris, Maike; Jonkers, Niels; Giger, Walter; Guenther, Klaus; Kohler, Hans-Peter E.

    2007-01-01

    Recently we showed that degradation of several nonylphenol isomers with α-quaternary carbon atoms is initiated by ipso-hydroxylation in Sphingobium xenophagum Bayram (F. L. P. Gabriel, A. Heidlberger, D. Rentsch, W. Giger, K. Guenther, and H.-P. E. Kohler, J. Biol. Chem. 280:15526-15533, 2005). Here, we demonstrate with 18O-labeling experiments that the ipso-hydroxy group was derived from molecular oxygen and that, in the major pathway for cleavage of the alkyl moiety, the resulting nonanol metabolite contained an oxygen atom originating from water and not from the ipso-hydroxy group, as was previously assumed. Our results clearly show that the alkyl cation derived from the α-quaternary nonylphenol 4-(1-ethyl-1,4-dimethyl-pentyl)-phenol through ipso-hydroxylation and subsequent dissociation of the 4-alkyl-4-hydroxy-cyclohexadienone intermediate preferentially combines with a molecule of water to yield the corresponding alcohol and hydroquinone. However, the metabolism of certain α,α-dimethyl-substituted nonylphenols appears to also involve a reaction of the cation with the ipso-hydroxy group to form the corresponding 4-alkoxyphenols. Growth, oxygen uptake, and 18O-labeling experiments clearly indicate that strain Bayram metabolized 4-t-butoxyphenol by ipso-hydroxylation to a hemiketal followed by spontaneous dissociation to the corresponding alcohol and p-quinone. Hydroquinone effected high oxygen uptake in assays with induced resting cells as well as in assays with cell extracts. This further corroborates the role of hydroquinone as the ring cleavage intermediate during degradation of 4-nonylphenols and 4-alkoxyphenols. PMID:17369338

  15. ortho-Lithium/magnesium carboxylate-driven aromatic nucleophilic substitution reactions on unprotected naphthoic acids.

    PubMed

    Aissaoui, Regadia; Nourry, Arnaud; Coquel, Ariane; Dao, Thi Thanh Hà; Derdour, Aicha; Helesbeux, Jean-Jacques; Duval, Olivier; Castanet, Anne-Sophie; Mortier, Jacques

    2012-01-06

    Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good to excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO(2)H) group. This novel nucleophilic aromatic substitution is presumed to proceed via a precoordination of the organometallic with the substrate, followed by an addition/elimination.

  16. Soluble, semivolatile phenol and nitrogen compounds in milk-processing wastewaters.

    PubMed

    Verheyen, V; Cruickshank, A; Wild, K; Heaven, M W; McGee, R; Watkins, M; Nash, D

    2009-07-01

    Potable water is an essential and major input in processing our food supplies, and the continued growth in food manufacturing is placing increased pressure on this limited resource. Recycling and reuse of factory wastewater can lessen potable water use but requires a detailed understanding of wastewater properties. This study uses solid-phase extraction techniques with gas chromatography-mass spectrometry analysis to investigate trace-level semivolatile organic species in various waste and reference waters associated with the Burra Foods milk-processing plant located in Southeastern Australia. Our focus was on contaminants containing phenolic and heterocyclic nitrogen functional groups, which, because of their toxicity and persistence, may limit options for water recycling and reuse. Effluent from the wastewater treatment plant of the factory showed both the highest soluble carbon burden (47 mg/kg) and concentrations of target compounds. The target species found in these effluents included methyl phenol (13 mg/kg), hydroxy indole (9.8 mg/kg), synthetic tolyltriazoles (5.1 mg/kg) and alkyl phenol ethoxylates (0.2 mg/kg). Given the environmental stability of the tolyltriazoles, they may act as chemical markers where these effluents are used for purposes such as irrigation. Milk evaporator condensate waters, in contrast to the effluent, contained very few target species, with only low levels of pyrrolidine and piperidine derivatives such as ethylglutarimide (450 mug/L) detected. Although there were fewer target microcontaminants overall in the potable and creek reference waters, these samples had characteristic profiles. The potable water analysis revealed hydroxy cineole (2.1 microg/L) and the creek analysis revealed dichlorohydroxyacetophenone (0.3 microg/L), which were not detected in other waters. The compounds found in the wastewaters are likely to have been derived from milk or synthetic chemicals used in factory operations. The presence of nitrogen compounds in

  17. Structure-activity relationships of alkylxanthines: alkyl chain elongation at the N1- or N7-position decreases cardiotonic activity in the isolated guinea pig heart.

    PubMed

    Sanae, F; Ohmae, S; Kurita, M; Sawanishi, H; Takagi, K; Miyamoto, K

    1995-10-01

    Relationships between the alkyl substitutions (C1-C6) and cardiac inotropic activities of xanthine derivatives were studied in isolated guinea pig heart muscles. Most of the alkylxanthines exhibited positive inotropic activity on the left atrium, which was increased with an elongation of alkyl chain at the N3-position but decreased by substitution of a long alkyl group at the N1- or N7-position of the xanthine skeleton. Although positive inotropic activity in the right ventricular papillary muscle was also increased by longer alkyl groups at the N3-position, the inotropic activity became negative with an increment in alkyl chain length at the N1- or N7-position. The positive inotropic activity of alkylxanthines was correlated with their inhibitory activity on the phosphodiesterase (PDE) III isoenzyme. Adenosine A1 antagonism and PDE IV inhibitory activity were also partly associated with the inotropic activity because H-89, an inhibitor of cyclic AMP-dependent protein kinase, diminished the positive inotropic action and potentiated the negative inotropic action. These results indicate that the positive inotropic activity of alkylxanthines becomes weak with elongation of alkyl chains at the N1- and N7-positions; In particular, xanthines having two long alkyl chains show a negative inotropic activity on the right ventricular papillary muscle, an effect that could not be elucidated from their cyclic AMP-dependent action.

  18. Binding of phenol and differently halogenated phenols to dissolved humic matter as measured by NMR spectroscopy.

    PubMed

    Smejkalová, Daniela; Spaccini, Riccardo; Fontaine, Barbara; Piccolo, Alessandro

    2009-07-15

    1H- and 19F-NMR measurements of spin-lattice (T1) and spin-spin (T2) relaxationtimes and diffusion ordered spectroscopy (DOSY) were applied to investigate the association of nonsubstituted (phenol (P)) and halogen-substituted (2,4-dichlorophenol (DCP); 2,4,6-trichlorophenol (TCP), and 2,4,6-trifluorophenol (TFP) phenols with a dissolved humic acid (HA). T1 and T2 values for both 1H and 19F in phenols decreased with enhancing HA concentration, indicating reduction in molecular mobility due to formation of noncovalent interactions. Moreover, correlation times (tau c) for different hydrogen and fluorine atoms in phenols showed that anisotropic mobility turned into isotropic motion with HA additions. Changes in relaxation times suggested that DCP and TCP were more extensively bound to HA than P and TFP. This was confirmed by diffusion measurements which showed full association of DCP and TCP to a less amount of HA than that required for entire complexation of P and TFP. Calculated values of binding constants (Ka) reflected the overall NMR behavior, being significantly larger for DCP- and TCP-HA (10.04 +/- 1.32 and 4.47 +/- 0.35 M(-1), respectively) than for P- and TFP-HA complexes (0.57 +/- 0.03 and 0.28 +/- 0.01 M(-1), respectively). Binding increased with decreasing solution pH, thus indicating a dependence on the fraction of protonated form (alpha) of phenols in solution. However, it was found that the hydrophobicity conferred to phenols by chlorine atoms on aromatic rings is a stronger drive than alpha for the phenols repartition within the HA hydrophobic domains.

  19. Ecofriendly approach for detection of phenols in water using laccase from different fungi.

    PubMed

    Kidwai, Mazaahir; Jain, Arti; Sharma, Abha; Chander Kuhad, Ramesh

    2012-01-01

    Laccase-initiated oxidative coupling reactions of phenol and its derivatives with 4-aminoantipyrene using air as an oxidant has been investigated. The oxidation reaction of phenols and 4-aminoantipyrene is getting a lot of attention due to environmental concerns. Oxidation of simple phenol and 4-aminoantipyrene as a benchmark reaction enabled us to rank the relative oxidation ability of various laccases. Among the laccases tested, laccase from Pycnoporus cinnabarinus successfully yielded 72% antipyrilquinoneimine dye. The present method can also be used to determine p-substituted phenols and chlorophenols. In this work, the influence of mediators on laccase activity has also been studied.

  20. EFFECT OF A FERROCENYL SUBSTITUTE ON THE FUNCTIONAL GROUPS IN THE BENZENE RING,

    DTIC Science & Technology

    and ferrocenylphenol with phenol and p-hydroxydiphenyl (p- phenylphenol ), indicating that the ferrocenyl group introduced into the benzene ring behaves as a distinctly expressed substitute of the first order.

  1. Novel 7-substituted coumarin compounds and an improved method for their synthesis. [Patent application

    SciTech Connect

    Bissell, E.R.

    1982-01-20

    Novel substituted coumarin compounds and an improved method for their synthesis are disclosed. The preferred class of compounds are substituted at the 7-position. The method of synthesis comprises reacting a polyhydroxy benzene or a substituted phenol, with a ..beta..-alkoxy acrylic acid or nitrile, in the presence of a Lewis acid catalyst. By the inclusion of the catalyst in the reaction mixture, the reaction can be carried out under much milder experimental conditions and in increased yields. The method is also applicable to the preparation of substituted amino phenols.

  2. Control of product selectivity using solid acids for the catalytic addition of phenol to hydroxy fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The acid catalyzed reactions of hydroxy fatty acids, such as ricinoleic and lesquerolic, in the presence of phenolics can lead to four products or product groups. These include simple dehydration to dienoic acids, cyclization to epoxides, Friedel-Crafts alkylations of the double bonds, or ether for...

  3. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  4. 21 CFR 176.120 - Alkyl ketene dimers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Alkyl ketene dimers. 176.120 Section 176.120 Food... Use Only as Components of Paper and Paperboard § 176.120 Alkyl ketene dimers. Alkyl ketene dimers may... section. (a) The alkyl ketene dimers are manufactured by the dehydrohalogenation of the acyl...

  5. Bioassay of Phenol for Possible Carcinogenicity (CAS No.108-95-2).

    PubMed

    1980-08-01

    Phenol ranked 38th in production among U.S. chemicals in 1978 with annual production of 2.38 billion pounds. Approximately 90% of the phenol produced is used in the manufacture of phenolic (phenol formaldehyde) resins, caprolactam, bisphenol A, alkyl phenol, and adipic acid. The remainder of the phenol is used to produce an assortment of end products, including salicylic acid, phenacetin, dyes, metal cleaners, disinfectants, antiseptics, photographic chemicals, wood preservatives (pentachlorophenol), paints, paint and varnish removers, and agricultural chemicals (2,4-D and parathion). A bioassay of phenol to test for possible carcinogenicity was conducted by providing this substance in drinking water to F344 rats and B6C3F1 mice. Groups of 50 rats and 50 mice of each sex were given drinking water containing 2,500 or 5,000 ppm phenol for 103 weeks. As matched controls, groups of 50 rats and 50 mice of each sex received tap water. A dose-related depression in mean body weight gain occurred in rats and mice of each sex. Rats and mice given water containing phenol drank less than did the corresponding controls. A dose-related decrease in water consumption was observed for mice. An increased incidence of leukemia or lymphomas was detected in male rats and may have been associated with the administration of phenol. Although the incidence of these tumors in the low-dose group was significantly higher than that in controls, the incidence in the high-dose group was not. Thus an association with administration of phenol was not established. Under the conditions of this bioassay, phenol was not carcinogenic for either male or female F344 rats or male and female B6C3F1 mice. Levels of Evidence of Carcinogenicity: Male Rats: Negative Female Rats: Negative Male Mice: Negative Female Mice: Negative

  6. Ruthenium-catalyzed meta/ortho-selective C-H alkylation of azoarenes using alkyl bromides.

    PubMed

    Li, Gang; Ma, Xingxing; Jia, Chunqi; Han, Qingqing; Wang, Ya; Wang, Junjie; Yu, Liuyang; Yang, Suling

    2017-01-19

    meta/ortho-Selective CAr-H (di)alkylation reactions of azoarenes have been achieved via [Ru(p-cymene)Cl2]2 catalyzed ortho-metalation using various types of alkyl bromides. Particularly, dual meta-alkylation of azoarene and reduction offer an attractive strategy for the synthesis of meta-alkylanilines, which are difficult to access via traditional aniline functionalization methods.

  7. N-alkylated and O-alkylated regioisomers of 5-(hydroxyalkyl)pyrimidines: Synthesis and structural study

    NASA Astrophysics Data System (ADS)

    Meščić, Andrijana; Glavač, Danijel; Osmanović, Amar; Završnik, Davorka; Cetina, Mario; Makuc, Damjan; Plavec, Janez; Ametamey, Simon M.; Raić-Malić, Silvana

    2013-05-01

    Synthesis of novel 5-(2-hydroxyethyl) and 5-(3-hydroxypropyl) acyclic pyrimidine nucleosides is described. Introduction of penciclovir-like side chain in C-5 substituted pyrimidines occurred both at N-1 and O-2 position of pyrimidine moiety that was corroborated by correlation of signals in 2D HMBC spectra. Therefore, alkylation of 5-(acetoxyethyl)-4-methoxypyrimidin-2-one (2a) and 5-(acetoxypropyl)-4-methoxypyrimidin-2-one (2b) afforded mixture of N- and O-acyclic pyrimidine nucleosides in the ratio of 49: 45 (4a: 5a) and 41: 21 (4b: 5b). Structures of 5-(acetoxyalkyl)-4-methoxypyrimidin-2-ones, as the first examples of 4-methoxypyrimidin-2-ones, were unambiguously confirmed by single crystal X-ray diffraction analysis.

  8. Hypercrosslinked phenolic polymers with well developed mesoporous frameworks

    DOE PAGES

    Zhang, Jinshui; Qiao, Zhenan -An; Mahurin, Shannon Mark; ...

    2015-02-12

    A soft chemistry synthetic strategy based on a Friedel Crafts alkylation reaction is developed for the textural engineering of phenolic resin (PR) with a robust mesoporous framework to avoid serious framework shrinkage and maximize retention of organic functional moieties. By taking advantage of the structural benefits of molecular bridges, the resultant sample maintains a bimodal micro-mesoporous architecture with well-preserved organic functional groups, which is effective for carbon capture. Furthermore, this soft chemistry synthetic protocol can be further extended to nanotexture other aromatic-based polymers with robust frameworks.

  9. N-Alkylation by Hydrogen Autotransfer Reactions.

    PubMed

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed.

  10. Perylene occurrence, alkylation and possible sources in deep-ocean sediments

    NASA Astrophysics Data System (ADS)

    Louda, J. William; Baker, Earl W.

    1984-05-01

    81 deep-ocean sediment samples obtained from the DSDP/IPOD program Legs 63-66, and six gravity-cores from DSDP/IPOD Leg 64 Guaymas Basin, Gulf of California, site survey cruise (SIO) were analyzed for perylene(s). Perylene was found to be most abundant in anoxic diatomaceous sediments containing moderate amounts of silts and/or clays. Elevated perylene yields, normalized to organic carbon contents, coincided with enhanced preservation of autochthonous tetraterpenoid and tetrapyrrole pigments, indicating a requirement of anoxia in the formation of perylene. Strongly euxinic conditions correlate with decreased perylene yields but not its total absence, as found for strongly aerobic deposition and/or redeposition. Perylene alkylation occurs in response to increasing in situ temperatures (alt. sub-bottom depth). This alkylation was found to begin with the generation of methyl (C-1) perylene and to eventually yield a perylene-alkyl perylene homologous series, in decreasing abundance, through the equivalent of C-3 (trimethyl, methyl-ethyl, propyl?) perylene. The realm of most intense perylene alkylation for Quaternary or Pliocene/ Miocene sediments corresponds with present in situ temperatures of 40-50°C or 30-35°C, respectively. Thus, the degree of perylene alkylation may represent an organic indicator for the thermal history of immature sediments. Geological phenomena, such as reworking and igneous intrusions, were found to complicate downhole perylene alkylation patterns. A substituted (-C 4H 7O 2) perylene was isolated from several anoxically deposited diatomaceous oozes and may represent one of the many possible perylene precursors. The possible source compounds and biota for sedimentary perylene are discussed in light of the present study and review of past reports.

  11. Biological aromatization of delta4,6- and delta1,4,6-androgens and their 6-alkyl analogs, potent inhibitors of aromatase.

    PubMed

    Numazawa, M; Yoshimura, A

    1999-01-01

    Enzymic aromatization of delta6- and delta1,6-derivatives of the natural substrate androstenedione with human placental aromatase was first studied using gas-chromatography-mass spectrometry. The two steroids were aromatized with apparent Km and Vmax values of 62 nM and 32 pmol/min/mg protein for the delta6-steroid and 167 nM and 10 pmol/min/mg protein for the delta1,6-steroid, respectively. We next explored the aromatization of a series of 6-alkyl (methyl, ethyl, n-propyl, and n-pentyl)-substituted delta6-androstenediones and their delta1,6-analogs, potent competitive inhibitors of aromatase, to gain insight into the relationships between the inhibitory activity of the 6-alkyl-C19 steroids and their ability to serve as a substrate of aromatase. In a series of the delta1,6-androstenediones, all the 6-alkyl steroids were more efficient substrates than the parent delta1,6-steroid in which the aromatization rates of the alkyl steroids were about 2-fold that of the parent steroid, in contrast, all of the 6-alkyl-substituted delta6-androstenediones were converted into the corresponding 6-alkyl-delta6-estrogens with the rates of less than about a half that of the parent steroid. These results indicate that the 6-alkyl function decreases the aromatization rate of the delta6-steroid but enhances that of the delta1,6-steroid. The relative apparent Km values for the C19 steroids obtained in this study are different from the relative Ki values obtained previously, indicating that a good inhibitor is not essentially a good substrate in the 6-alkyl-substituted delta6- and delta1,6-androstenedione series.

  12. [Synthesis, characterization and fluorescent properties of copper phthalocyanine derivates substituted by aliphatic alcohol].

    PubMed

    Zhang, Liang; Xu, Qing-Feng; Lu, Jian-Mei; Yao, She-Chun

    2007-04-01

    A series of copper phthalocyanine derivatives substituted by aliphatic chain were obtained by the reaction of tetra-formyl chloride copper phthalocyanine and aliphatic alcohol such as n-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-caprylic alcohol and lauryl alcohol. IR, UV-Vis, elemental analysis and 1H NMR verified the structures and substituting degree. The solubility and the relationship between fluorescence and concentration and substituting group were studied in organic solution. It was confirmed that the solubility in organic solution was improved greatly, the fluorescence did not change in linear according to the concentration and the fluorescence of copper phthalocyanine derivatives substituted by the long alkyl was stronger than that substituted by the relatively short alkyl.

  13. Kinetics of phenolic polymerization catalyzed by peroxidase in organic media

    SciTech Connect

    Xu, Y.P.; Huang, G.L; Yu, Y.T.

    1995-07-05

    Phenolic polymerization was carried out by enzymatic catalysis in organic media, and its kinetics was studied by using high-pressure liquid chromatography (HPLC). Phenols and aromatic amines with electron-withdrawing groups could hardly be polymerized by HRP catalysis, but phenols and aromatic amines with electron-donating groups could easily by polymerized. The reaction rate of either the para-substituted substrate or meta-substituted substrate was higher than that of ortho-substituted substrate. When ortho-position of hydroxy group of phenols was occupied by an electron-donating group and if another electron-donating group occupied para-position of hydroxy group, the reaction rate increased. Horseradish peroxidase and lactoperoxidase could easily catalyze the polymerization, but chloroperoxidase and laccase failed to yield polymers. Metallic ions such as Mn{sup 2+}, Fe{sup 2+}, or Fe{sup 3+}, and Cu{sup 2+} could poison horseradish peroxidase to various extents, but ions such as Co{sup 2+}, Cd{sup 2+}, Zn{sup 2+}, and K{sup +} were not found to inhibit the reaction.

  14. Simple, heart-smart substitutions

    MedlinePlus

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart smart substitutions; Wellness - heart smart substitutions

  15. Iridium-Catalyzed Allylic Substitution

    NASA Astrophysics Data System (ADS)

    Hartwig, John F.; Pouy, Mark J.

    Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

  16. Copper-catalyzed oxidative C-O bond formation of 2-acyl phenols and 1,3-dicarbonyl compounds with ethers: direct access to phenol esters and enol esters.

    PubMed

    Park, Jihye; Han, Sang Hoon; Sharma, Satyasheel; Han, Sangil; Shin, Youngmi; Mishra, Neeraj Kumar; Kwak, Jong Hwan; Lee, Cheong Hoon; Lee, Jeongmi; Kim, In Su

    2014-05-16

    A copper-catalyzed oxidative coupling of 2-carbonyl-substituted phenols and 1,3-dicarbonyl compounds with a wide range of dibenzyl or dialkyl ethers is described. This protocol provides an efficient preparation of phenol esters and enol esters in good yields with high chemoselectivity. This method represents an alternative protocol for classical esterification reactions.

  17. Ring-opening reactions of 1,4-diazabicyclo[2.2.2]octane (DABCO) derived quaternary ammonium salts with phenols and related nucleophiles.

    PubMed

    Maraš, Nenad; Polanc, Slovenko; Kočevar, Marijan

    2012-02-14

    1,4-Diazabicyclo[2.2.2]octane (DABCO) has been evaluated as a starting material for the synthesis of 1-alkyl-4-(2-phenoxyethyl)piperazines and related derivatives. We found that 1-alkyl-1,4-diazabicyclo[2.2.2]octan-1-ium salts, resulting from the alkylation of DABCO, efficiently react with a variety of nucleophiles in polyethyleneglycol (PEG) or diglyme at high temperatures to give piperazine products resulting from the nucleophilic ring-opening reaction. The benzylation side reaction was found to be relevant with softer nucleophiles when using 1-benzyl-1,4-diazabicyclo[2.2.2]octan-1-ium salts, while other types of alkylations were not observed. One-pot methodologies allow for the synthesis of piperazines directly from primary alcohols, alkyl halides or sulfonates, using phenols, or other nucleophile sources, and DABCO.

  18. Phenolics and plant allelopathy.

    PubMed

    Li, Zhao-Hui; Wang, Qiang; Ruan, Xiao; Pan, Cun-De; Jiang, De-An

    2010-12-07

    Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  19. Synthesis and characterization of a cyclobutane duocarmycin derivative incorporating the 1,2,10,11-tetrahydro-9H-cyclobuta[c]benzo[e]indol-4-one (CbBI) alkylation subunit.

    PubMed

    Lajiness, James P; Boger, Dale L

    2010-10-06

    The synthesis of 1,2,10,11-tetrahydro-9H-cyclobuta[c]benzo[e]indol-4-one (17, CbBI), which contains a deep-seated fundamental structural modification in the CC-1065 and duocarmycin alkylation subunit consisting of the incorporation of a ring-expanded fused cyclobutane (vs cyclopropane), its chemical and structural characterization, and its incorporation into a key analogue of the natural products are detailed. The approach to the preparation of CbBI was based on a precedented (Ar-3' and Ar-5') but previously unknown Ar-4' spirocyclization of a phenol onto a tethered alkyl halide to form the desired cyclobutane. The conditions required for the implementation of the Ar-4' spirocyclization indicate that the entropy of activation substantially impacts the rate of reaction relative to that for the much more facile Ar-3' spirocyclization, while the higher enthalpy of activation slows the reaction relative to an Ar-5' spirocyclization. The characterization of the CbBI-based agents revealed their exceptional stability and exquisite reaction regioselectivity, and a single-crystal X-ray structure analysis of N-Boc-CbBI (13) revealed their structural origins. The reaction regioselectivity may be attributed to the stereoelectronic alignment of the two available cyclobutane bonds with the cyclohexadienone π-system, which resides in the bond that extends to the less substituted cyclobutane carbon for 13. The remarkable stability of N-Boc-CbBI (which is stable even at pH 1) relative to N-Boc-CBI containing a cyclopropane (t(1/2) = 133 h at pH 3) may be attributed to a combination of the increased extent of vinylogous amide conjugation, the nonoptimal geometric alignment of the cyclobutane with the activating cyclohexadienone, and the intrinsic but modestly lower strain energy (1.8 kcal/mol) of a cyclobutane versus a cyclopropane.

  20. Ligand-Accelerated ortho-C–H Alkylation of Arylcarboxylic Acids Using Alkyl Boron Reagents

    PubMed Central

    Thuy-Boun, Peter S.; Villa, Giorgio; Dang, Devin; Richardson, Paul; Su, Shun; Yu, Jin-Quan

    2013-01-01

    A protocol for the Pd(II)-catalyzed ortho-C–H alkylation of phenylacetic and benzoic acids using alkylboron reagents is disclosed. Mono-protected amino acid ligands (MPAA) were found to significantly promote reactivity. Both potassium alkyltrifluoroborates and alkylboronic acids were compatible coupling partners. The possibility of a radical alkyl transfer to Pd(II) was also investigated. PMID:24124892

  1. Enantioselective Multicomponent Condensation Reactions of Phenols, Aldehydes, and Boronates Catalyzed by Chiral Biphenols.

    PubMed

    Barbato, Keith S; Luan, Yi; Ramella, Daniele; Panek, James S; Schaus, Scott E

    2015-12-04

    Chiral diols and biphenols catalyze the multicomponent condensation reaction of phenols, aldehydes, and alkenyl or aryl boronates. The condensation products are formed in good yields and enantioselectivities. The reaction proceeds via an initial Friedel-Crafts alkylation of the aldehyde and phenol to yield an ortho-quinone methide that undergoes an enantioselective boronate addition. A cyclization pathway was discovered while exploring the scope of the reaction that provides access to chiral 2,4-diaryl chroman products, the core of which is a structural motif found in natural products.

  2. Enantioselective Multicomponent Condensation Reactions of Phenols, Aldehydes, and Boronates Catalyzed by Chiral Biphenols

    PubMed Central

    Barbato, Keith S.; Luan, Yi; Ramella, Daniele; Panek, James S.; Schaus, Scott E.

    2015-01-01

    Chiral diols and biphenols catalyze the multicomponent condensation reaction of phenols, aldehydes, and alkenyl or aryl boronates. The condensation products are formed in good yields and enantioselectivities. The reaction proceeds via an initial Friedel Crafts alkylation of the aldehyde and phenol to yield an ortho-quinone methide that undergoes an enantioselective boronate addition. A cyclization pathway was discovered while exploring the scope of the reaction that provides access to chiral 2,4-diaryl chroman products, the core of which is a structural motif found in natural products. PMID:26576776

  3. Mechanism of phenol oxidation by heterodinuclear Ni Cu bis(μ-oxo) complexes involving nucleophilic oxo groups

    PubMed Central

    Kundu, Subrata; Miceli, Enrico; Farquhar, Erik R.

    2014-01-01

    Oxidation of phenols by heterodinuclear CuIII(μ-O)2NiIII complexes containing nucleophilic oxo groups occurs by both proton coupled electron transfer (PCET) and hydrogen atom transfer (HAT) mechanisms; the exact mechanism depends on the nature of the phenol as well as the substitution pattern of the ligand bound to Cu. PMID:24362244

  4. Interplay between alkyl chain asymmetry and cholesterol addition in the rigid ion pair amphiphile bilayer systems

    NASA Astrophysics Data System (ADS)

    Huang, Fong-yin; Chiu, Chi-cheng

    2017-01-01

    Ion pair amphiphile (IPA), a molecular complex composed of a pair of cationic and anionic surfactants, has been proposed as a novel phospholipid substitute. Controlling the physical stability of IPA vesicles is important for its application developments such as cosmetic and drug deliveries. To investigate the effects of IPA alkyl chain combinations and the cholesterol additive on the structural and mechanical properties of IPA vesicular bilayers, we conducted a series of molecular dynamics studies on the hexadecyltrimethylammonium-dodecylsulfate (HTMA-DS) and dodecyltrimethylammonium-hexadecylsulfate (DTMA-HS) IPA bilayers with cholesterol. We found that both IPA bilayers are in the gel phase at 298 K, consistent with experimental observations. Compared with the HTMA-DS system, the DTMA-HS bilayer has more disordered alkyl chains in the hydrophobic region. When adding cholesterol, it induces alkyl chain ordering around its rigid sterol ring. Yet, cholesterol increases the molecular areas for all species and disturbs the molecular packing near the hydrophilic region and the bilayer core. Cholesterol also promotes the alkyl chain mismatch between the IPA moieties, especially for the DTMA-HS bilayer. The combined effects lead to non-monotonically enhancement of the membrane mechanical moduli for both IPA-cholesterol systems. Furthermore, cholesterol can form H-bonds with the alkylsulfate and thus enhance the contribution of alkylsulfate to the overall mechanical moduli. Combined results provide valuable molecular insights into the roles of each IPA component and the cholesterol on modulating the IPA bilayer properties.

  5. Alkylation of isobutane with light olefins: Yields of alkylates for different olefins

    SciTech Connect

    Albright, L.F.; Kranz, K.E.; Masters, K.R.

    1993-12-01

    For alkylation of isobutane with C{sub 3}-C{sub 5} olefins using sulfuric acid as the catalyst, the yields of alkylates with different olefins are compared as the operating conditions are changed. The results of recent pilot plant experiments with propylene, C{sub 4} olefins, and C{sub 5} olefins permit such comparisons. The yields expressed as weight of alkylate produced per 100 wt of olefin consumed varied from about 201:100 to 220:100. Weight ratios of the isobutane consumed per olefin consumed vary from about 101:100 to 120:100. differences of yield values are explained by the changes in the overall chemistry. The procedure employed to calculate yields with good accuracy is based on the analysis of the alkylate and the amount of conjunct polymers produced. Based on literature data, yields are also reported for alkylations using HF as the catalyst.

  6. N-Chlorosuccinimide-mediated oxidative chlorination of thiols to Nα-protected amino alkyl sulfonyl azides and their utility in the synthesis of sulfonyl triazole acids.

    PubMed

    Sharnabai, K M; Krishnamurthy, M; Sagar, N R; Santhosh, L; Vommina, Sureshbabu V

    2016-11-30

    An efficient oxidative chlorination of thiols to Nα-protected amino alkyl sulfonyl azides is delineated. The reaction involves in situ generation of sulfonyl chloride employing N-chlorosuccinimide and tetrabutylammonium chloride-water in acetonitrile, followed by the reaction with sodium azide. The protocol is simple, straight forward, mild and high yielding. Amino acids with simple as well as bifunctional side chains were used to obtain Nα-protected amino alkyl sulfonyl azides. Further, sulfonyl azides were utilized to synthesize unnatural amino acids via Cu(OAc)2.H2O/2-amino phenol catalyzed Click reaction with propiolic acid.

  7. Proton transfer in phenol-amine complexes: phenol electronic effects on free energy profile in solution.

    PubMed

    Aono, Shinji; Kato, Shigeki

    2010-12-01

    Free energy profiles for the proton transfer reactions in hydrogen-bonded complex of phenol with trimethylamine in methyl chloride solvent are studied with the reference interaction site model self-consistent field method. The reactions in both the electronic ground and excited states are considered. The second-order Møller-Plesset perturbation (MP) theory or the second-order multireference MP theory is used to evaluate the effect of the dynamical electron correlation on the free energy profiles. The free energy surface in the ground state shows a discrepancy with the experimental results for the related hydrogen-bonded complexes. To resolve this discrepancy, the effects of chloro-substitutions in phenol are examined, and its importance in stabilizing the ionic form is discussed. The temperature effect is also studied. In contrast to the ground state, the ππ* excited state of phenol-trimethylamine complex exhibits the proton transfer reaction with a low barrier. The reaction is almost thermoneutral. This is attributed to the reduction of proton affinity of phenol by the ππ* electronic excitation. We further examine the possibility of the electron-proton-coupled transfer in the ππ* state through the surface crossing with the charge transfer type πσ* state.

  8. Visible Light Copper Photoredox-Catalyzed Aerobic Oxidative Coupling of Phenols and Terminal Alkynes: Regioselective Synthesis of Functionalized Ketones via C≡C Triple Bond Cleavage.

    PubMed

    Sagadevan, Arunachalam; Charpe, Vaibhav Pramod; Ragupathi, Ayyakkannu; Hwang, Kuo Chu

    2017-03-01

    Direct oxidative coupling of phenols and terminal alkynes was achieved at room temperature by a visible-light-mediated copper-catalyzed photoredox process. This method allows regioselective synthesis of hydroxyl-functionalized aryl and alkyl ketones from simple phenols and phenylacetylene via C≡C triple bond cleavage. 47 examples were presented. From a synthetic perspective, this protocol offers an efficient synthetic route for the preparation of pharmaceutical drugs, such as pitofenone and fenofibrate.

  9. Gas chromatographic retention characteristics of phenols with Superox-20M

    SciTech Connect

    White, C.M.; Li, N.C.

    1982-08-01

    The gas chromatographic retention characteristics of a variety of underivatized phenols have been studied by using Superox-20M coated on fused silica. The relative retention times of thes compounds were measured at 160, 150, and 140/sup 0/C in order to determine the effect of operating temperature on relative retention. This information is used to predict relative retention times of phenols for which we had no standards. The linear temperature-programmed retention indexes of the solutes were measured. The retention of phenols on this phase is a function of the compounds vapor pressure, its ability to hydrogen bond with the stationary phase, and the strengths of those hydrogen bonds. These properties are in turn governed by steric, inductive, and resonance effects of the substituents. Linear free-energy relations between the logarithm of the ratio of the activity coefficients of phenol to substituted phenol (calculated from relative retention data) and the chromatographic substituent constant, sigma/sub c/, have been determined for some phenols on Superox-20M. Lastly, it was shown by nuclear magnetic resonance experiments that Superox-20M is apparently a poly(ethylene glycol) (also called a polyoxiran or poly(ethylene oxide)). 5 figures, 3 tables.

  10. Phenol removal from refinery wastewater by mutant recombinant horseradish peroxidase.

    PubMed

    Asad, Sedigheh; Dabirmanesh, Bahareh; Khajeh, Khosro

    2014-01-01

    Application of mutated recombinant horseradish peroxidase (HRP) for phenol removal from refinery effluents is reported. Recombinant HRP produced in Escherichia coli suffers from the disadvantage of lacking glycosylation, which affects its catalytic efficiency and stability toward inactivating parameters such as increased temperature and enhanced amounts of hydrogen peroxide. In the present study, the previously reported variant (in which Asn268 was substituted with Asp, N268D) with improved stability characteristics and catalytic efficiency was used to remove phenol from a petroleum refinery effluent. The presence and removal of phenol was studied by high-performance liquid chromatography; the precipitated oxidized phenol was also observed and removed from the sample by centrifugation. Results showed that the N268D variant can remove 61%, 67%, and 81% of phenol from effluent in 1, 2, and 16 H, respectively. By exploiting the N268D mutant, removal of 50% phenol could be achieved in 42 Min, which was more than 22 times less than the treatment time required by native recombinant enzyme.

  11. Improving the alkaline stability of imidazolium cations by substitution.

    PubMed

    Dong, Huilong; Gu, Fenglou; Li, Min; Lin, Bencai; Si, Zhihong; Hou, Tingjun; Yan, Feng; Lee, Shuit-Tong; Li, Youyong

    2014-10-06

    Imidazolium cations are promising candidates for preparing anion-exchange membranes because of their good alkaline stability. Substitution of imidazolium cations is an efficient way to improve their alkaline stability. By combining density functional theory calculations with experimental results, it is found that the LUMO energy correlates with the alkaline stability of imidazolium cations. The results indicate that alkyl groups are the most suitable substituents for the N3 position of imidazolium cations, and the LUMO energies of alkyl-substituted imidazolium cations depend on the electron-donating effect and the hyperconjugation effect. Comparing 1,2-dimethylimidazolium cations (1,2-DMIm+) and 1,3-dimethylimidazolium cations (1,3-DMIm+) with the same substituents reveals that the hyperconjugation effect is more significant in influencing the LUMO energy of 1,3-DMIms. This investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations.

  12. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  13. Bread formulated with guava powder was enriched in phenolic and aroma compounds, and was highly acceptable by consumers.

    PubMed

    Castelo-Branco, Vanessa N; Lago, Mabel G; Minuzzo, Daniela A; Moura-Nunes, Nathália; Torres, Alexandre G; Nunes, Juliana C; Monteiro, Mariana

    2016-12-01

    Guava powder (GP) was used as source of aroma and phenolic compounds to fortify wheat bread 10% (GB10) and 20% (GB20), substituting for wheat flour. Phenolic compounds, antioxidant capacity, volatile compounds profile, and sensory acceptability of control bread (CB; without GP) and guava breads (GB) were evaluated. Incorporation of GP increased roughly 2-to-3-fold the phenolic compounds contents of bread. Ten phenolic compounds were identified in GB20, and quercetin-3-O-rutinoside was the major compound, while in CB, ferulic acid was the major among the six phenolic compounds in CB. Bread making seemed to promote the release of phenolic compounds from structural components. Breads incorporated with GP presented a richer volatile profile than CB, especially due to the presence of terpenes. GB improved aroma profile of bread. GP added aroma compounds and phenolic antioxidants, and seemed to be an interesting approach to enhance bread bioactivity and acceptability.

  14. Synthesis, characterization, solvatochromism and biological properties of 2,2‧-((1E,1‧E)-((1,2,5-oxadiazole-3,4-diyl)bis (azanylylidene))bis(methan-ylylidene))bis(4-(phenyldiazenyl)phenol)

    NASA Astrophysics Data System (ADS)

    Kakanejadifard, Ali; Azarbani, Farideh; Saki, Zeinab; Kakanejadifard, Sahar; Zabardasti, Abedin

    2014-11-01

    Azo-azomethine dyes 2-((4-amino-1,2,5-oxadiazol-3-ylimino)methyl)-4-(phenyl diazenyl)phenols (2a-h) have been synthesized by condensation reaction of 3,4-diamino-1,2,5-oxadiazole with 2-hydroxy-5-[(E)-(aryldiazenyl)]benzaldehyde (1a-h) in methanol. The structures of dyes have been characterized by elemental analysis, mass, IR, UV-Vis, 1H and 13С NMR spectroscopy. UV-Vis absorption spectra indicated enol-keto tautomeric and positive solvatochromism in compounds 2a-h which is dependent on the substitution, solvent, pH and environment temperature. The synthesized compounds were investigated for their in vitro antioxidant activity by diphenylpicrylhydrazyl assay. Compounds substituted with electron donating groups, such as, alkyl and methoxy groups showed moderate antioxidant activity. The in vitro antibacterial activity of all compounds was determined by disk diffusion method. The test compounds showed varying degree of inhibition against B. cereus and S. aureus strains.

  15. Synthesis, characterization, solvatochromism and biological properties of 2,2'-((1E,1'E)-((1,2,5-oxadiazole-3,4-diyl)bis (azanylylidene))bis(methan-ylylidene))bis(4-(phenyldiazenyl)phenol).

    PubMed

    Kakanejadifard, Ali; Azarbani, Farideh; Saki, Zeinab; Kakanejadifard, Sahar; Zabardasti, Abedin

    2014-11-11

    Azo-azomethine dyes 2-((4-amino-1,2,5-oxadiazol-3-ylimino)methyl)-4-(phenyl diazenyl)phenols (2a-h) have been synthesized by condensation reaction of 3,4-diamino-1,2,5-oxadiazole with 2-hydroxy-5-[(E)-(aryldiazenyl)]benzaldehyde (1a-h) in methanol. The structures of dyes have been characterized by elemental analysis, mass, IR, UV-Vis, 1H and 13С NMR spectroscopy. UV-Vis absorption spectra indicated enol-keto tautomeric and positive solvatochromism in compounds 2a-h which is dependent on the substitution, solvent, pH and environment temperature. The synthesized compounds were investigated for their in vitro antioxidant activity by diphenylpicrylhydrazyl assay. Compounds substituted with electron donating groups, such as, alkyl and methoxy groups showed moderate antioxidant activity. The in vitro antibacterial activity of all compounds was determined by disk diffusion method. The test compounds showed varying degree of inhibition against B. cereus and S. aureus strains.

  16. Removal of phenol from synthetic waste water using Gemini micellar-enhanced ultrafiltration (GMEUF).

    PubMed

    Zhang, Wenxiang; Huang, Guohe; Wei, Jia; Li, Huiqin; Zheng, Rubing; Zhou, Ya

    2012-10-15

    Comprehensive studies were conducted on the phenol wastewater ultrafiltration (UF) with the help of various concentrations of cationic Gemini surfactant (N1-dodecyl-N1,N1,N2,N2-tetramethyl-N2-octylethane-1,2-diaminium bromide, CG), conventional cationic surfactant (dodecyl trimethyl ammonium bromide, DTAB), anionic surfactant (sodium dodecyl sulfate, SDS) and nonionic surfactant ((dodecyloxy)polyethoxyethanol, Brij35). A flat sheet module with polyethersulfone (PES) membrane was employed in this investigation. The effects of feed concentration (phenol and surfactant) on the retention of phenol and surfactant, permeate flux and membrane fouling by micelles were evaluated. The distribution coefficient (D), the loading of the micelles (L(m)) and the equilibrium distribution constant (K) were also utilized to estimate the micellar-enhanced ultrafiltration ability for phenol. Scanning electron microscope (SEM), Fourier transform infrared spectrometer with attenuated total reflectance accessory (ATR-FTIR) and mercury porosimeter were applied to analyze membrane surface morphology, membrane material characteristics and membrane fouling for the original and fouled membranes. Based on the above analysis, the performance of the selected Gemini surfactant was proved superior in the following aspects: retention of phenol/surfactant (peak value is 95.8% for phenol retention), permeate flux and membrane fouling with respect to other conventional surfactants possessing equal alkyl chain length. These results demonstrated that CG surfactant with exceptional structure has favorable prospects in the treatment of phenol wastewater by the micellar-enhanced ultrafiltration.

  17. Chiral Alkyl Halides: Underexplored Motifs in Medicine

    PubMed Central

    Gál, Bálint; Bucher, Cyril; Burns, Noah Z.

    2016-01-01

    While alkyl halides are valuable intermediates in synthetic organic chemistry, their use as bioactive motifs in drug discovery and medicinal chemistry is rare in comparison. This is likely attributable to the common misconception that these compounds are merely non-specific alkylators in biological systems. A number of chlorinated compounds in the pharmaceutical and food industries, as well as a growing number of halogenated marine natural products showing unique bioactivity, illustrate the role that chiral alkyl halides can play in drug discovery. Through a series of case studies, we demonstrate in this review that these motifs can indeed be stable under physiological conditions, and that halogenation can enhance bioactivity through both steric and electronic effects. Our hope is that, by placing such compounds in the minds of the chemical community, they may gain more traction in drug discovery and inspire more synthetic chemists to develop methods for selective halogenation. PMID:27827902

  18. Sequence-specific DNA alkylation and transcriptional inhibition by long-chain hairpin pyrrole-imidazole polyamide-chlorambucil conjugates targeting CAG/CTG trinucleotide repeats.

    PubMed

    Asamitsu, Sefan; Kawamoto, Yusuke; Hashiya, Fumitaka; Hashiya, Kaori; Yamamoto, Makoto; Kizaki, Seiichiro; Bando, Toshikazu; Sugiyama, Hiroshi

    2014-09-01

    Introducing novel building blocks to solid-phase peptide synthesis, we readily synthesized long-chain hairpin pyrrole-imidazole (PI) polyamide-chlorambucil conjugates 3 and 4 via the introduction of an amino group into a GABA (γ-turn) contained in 3, to target CAG/CTG repeat sequences, which are associated with various hereditary disorders. A high-resolution denaturing polyacrylamide sequencing gel revealed sequence-specific alkylation both strands at the N3 of adenines or guanines in CAG/CTG repeats by conjugates 3 and 4, with 11bp recognition. In vitro transcription assays using conjugate 4 revealed that specific alkylation inhibited the progression of RNA polymerase at the alkylating sites. Chiral substitution of the γ-turn with an amino group resulted in higher binding affinity observed in SPR assays. These assays suggest that conjugates 4 with 11bp recognition has the potential to cause specific DNA damage and transcriptional inhibition at the alkylating sites.

  19. Sulfoalkyl ether-alkyl ether cyclodextrin derivatives, their synthesis, NMR characterization, and binding of 6alpha-methylprednisolone.

    PubMed

    Tongiani, Serena; Velde, David Vander; Ozeki, Tetsuya; Stella, Valentino J

    2005-11-01

    The objective of this study is to see if random alkyl ethers of various sulfoalkyl ether cyclodextrins can be synthesized and characterized. The purpose of the alkylation was to test the hypothesis that an increase in the "height" of a cyclodextrins cavity would help in the binding/complexation of larger more structurally complex molecules. The synthesis of new cyclodextrin derivatives comprising a mixture of sulfoalkyl ether and alkyl ether substituents on the same cyclodextrin ring was performed in aqueous alkaline solutions using various sultones and alkylsulfates. The method presented provided an easy and efficient way to modify cyclodextrins avoiding the use of organic solvents and high quantities of alkylating agents and could be carried out in either a two step or "one pot" single step process. Purification was by neutralization followed by ultrafiltration. The derivatives were characterized by 1D, ((1)H and (13)C), and a 2D NMR technique (HMQC, Heteronuclear Multiple Quantum Coherence). The combination of these techniques allowed an analysis of the degree of substitution and the site of substitution on the cyclodextrin (CD) nucleus. For both beta- and gamma-CD, sulfoakylation was preferred on the 2 > 3 > 6 hydroxyls while alkylation was preferred 6 > 2 > 3. Due to the simultaneous presence of short alkyl ether chains and negatively charged sulfoalkyl ether chains, these mixed water-soluble cyclodextrin derivatives, especially those of gamma-cyclodextrin, should be able to bind more complex drugs. The improved binding capacity of these new modified CDs with the model drug 6alpha-methylprednisolone is reported.

  20. Regioselective synthesis of C3 alkylated and arylated benzothiophenes

    NASA Astrophysics Data System (ADS)

    Shrives, Harry J.; Fernández-Salas, José A.; Hedtke, Christin; Pulis, Alexander P.; Procter, David J.

    2017-03-01

    Benzothiophenes are heterocyclic constituents of important molecules relevant to society, including those with the potential to meet modern medical challenges. The construction of molecules would be vastly more efficient if carbon-hydrogen bonds, found in all organic molecules, can be directly converted into carbon-carbon bonds. In the case of elaborating benzothiophenes, functionalization of carbon-hydrogen bonds at carbon-number 3 (C3) is markedly more demanding than at C2 due to issues of regioselectivity (C3 versus C2), and the requirement of high temperatures, precious metals and the installation of superfluous directing groups. Herein, we demonstrate that synthetically unexplored but readily accessible benzothiophene S-oxides serve as novel precursors for C3-functionalized benzothiophenes. Employing an interrupted Pummerer reaction to capture and then deliver phenol and silane coupling partners, we have discovered a directing group-free method that delivers C3-arylated and -alkylated benzothiophenes with complete regioselectivity, under metal-free and mild conditions.

  1. Regioselective synthesis of C3 alkylated and arylated benzothiophenes

    PubMed Central

    Shrives, Harry J.; Fernández-Salas, José A.; Hedtke, Christin; Pulis, Alexander P.; Procter, David J.

    2017-01-01

    Benzothiophenes are heterocyclic constituents of important molecules relevant to society, including those with the potential to meet modern medical challenges. The construction of molecules would be vastly more efficient if carbon–hydrogen bonds, found in all organic molecules, can be directly converted into carbon–carbon bonds. In the case of elaborating benzothiophenes, functionalization of carbon–hydrogen bonds at carbon-number 3 (C3) is markedly more demanding than at C2 due to issues of regioselectivity (C3 versus C2), and the requirement of high temperatures, precious metals and the installation of superfluous directing groups. Herein, we demonstrate that synthetically unexplored but readily accessible benzothiophene S-oxides serve as novel precursors for C3-functionalized benzothiophenes. Employing an interrupted Pummerer reaction to capture and then deliver phenol and silane coupling partners, we have discovered a directing group-free method that delivers C3-arylated and -alkylated benzothiophenes with complete regioselectivity, under metal-free and mild conditions. PMID:28317882

  2. Potential applications of immobilized bitter gourd (Momordica charantia) peroxidase in the removal of phenols from polluted water.

    PubMed

    Akhtar, Suhail; Husain, Qayyum

    2006-11-01

    The potential applications of immobilized bitter gourd peroxidase in the treatment of model wastewater contaminated with phenols have been investigated. The synthetic water was treated with soluble and immobilized enzyme preparations under various experimental conditions. Maximum removal of phenols was found in the buffers of pH values 5.0-6.0 and at 40 degrees C in the presence of 0.75 mM H(2)O(2). Fourteen different phenols were independently treated with soluble and immobilized bitter gourd peroxidase in the buffer of pH 5.6 at 37 degrees C. Chlorinated phenols and native phenol were significantly removed while other substituted phenols were marginally removed by the treatment. Phloroglucinol and pyrogallol were recalcitrant to the action of bitter gourd peroxidase. Immobilized bitter gourd peroxidase preparation was capable of removing remarkably high percentage of phenols from the phenolic mixtures. Significantly higher level of total organic carbon was removed from the model wastewater containing individual phenol or complex mixture of phenols by immobilized bitter gourd peroxidase as compared to the soluble enzyme. 2,4-dichlorophenol and a phenolic mixture were also treated in a stirred batch reactor with fixed quantity of enzyme for longer duration. The soluble bitter gourd peroxidase ceased to function after 3h while the immobilized enzyme was active even after 6h of incubation with phenolic solutions.

  3. Nickel-Catalyzed Allylic Substitution of Simple Alkenes

    PubMed Central

    Matsubara, Ryosuke; Jamison, Timothy F.

    2011-01-01

    This report describes a nickel-catalyzed allylic substitution process of simple alkenes whereby an important structural motif, a 1,4-diene, was prepared. A key for this success is the use of an appropriate Ni-phosphine complex and a stoichiometric amount of silyl triflate. Reactions of 1-alkyl-substituted alkenes consistently provided 1,1-disubstituted alkenes with high selectivity. Insight into the reaction mechanism as well as miscellaneous application of the developed catalytic process is also documented. PMID:21387565

  4. Transition metal-free decarboxylative alkylation reactions.

    PubMed

    Liu, Ping; Zhang, Guanghui; Sun, Peipei

    2016-11-22

    This review summarizes advances in the decarboxylative alkylation of carboxylic acids and their derivatives under transition metal-free conditions in recent years. Unlike most transition metal-catalyzed decarboxylative coupling reactions which tend to undergo catalytic cycles, the mechanisms of reactions under metal-free conditions are usually diverse and even ambiguous in some cases. This article offers an overview of reaction types and their corresponding mechanisms, highlights some of the advantages and limitations, and focuses on introducing UV and visible light-induced, organocatalyst and peroxide promoted radical processes for decarboxylative alkylation and the formation of C-C bonds.

  5. Alkyl ferulates in wound healing potato tubers.

    PubMed

    Bernards, M A; Lewis, N G

    1992-10-01

    Seven ferulic acid esters of 1-alkanols ranging in carbon length from C16 to C28 were synthesized and an HPLC protocol for their separation developed. Extracts prepared from wound healing potato (Solanum tuberosum) tubers and analysed by HPLC indicated that alkyl ferulate esters begin to accumulate 3-7 days after wound treatment. Of the nine esters identified by EIMS, (including two esters of odd chain length alkanols) hexadecyl and octadecyl ferulates were predominant. Alkyl ferulate esters were restricted to the wound periderm.

  6. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia

    2009-09-22

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  7. Enhancement of alkylation catalysts for improved supercritical fluid regeneration

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.

    2010-12-28

    A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

  8. Synthesis and DPPH radical scavenging activity of prenylated phenol derivatives.

    PubMed

    Osorio, Mauricio; Aravena, Jacqueline; Vergara, Alejandra; Taborga, Lautaro; Baeza, Evelyn; Catalán, Karen; González, Cesar; Carvajal, Marcela; Carrasco, Héctor; Espinoza, Luis

    2012-01-06

    The synthesis of twenty six prenylated phenols derivatives is reported. These compounds were obtained under mild conditions via Electrophilic Aromatic Substitution (EAS) coupling reactions between phenol derivatives containing electron-donor subtituents and 3-methyl-2-buten-1-ol using BF(3)×OEt(2). Dialkylations were also produced with this method. The formation of a chroman ring by intramolecular cyclization between a sp2 carbon from the prenyl group with the hydroxyl substituent in the ortho position occurred with some phenols. All the synthesized compounds were evaluated as antioxidants according to a DPPH radical scavenging activity assay. IC(50) values of five synthesized compounds indicated they were as good antioxidants as Trolox™.

  9. Vinylation of Unprotected Phenols Using a Biocatalytic System.

    PubMed

    Busto, Eduardo; Simon, Robert C; Kroutil, Wolfgang

    2015-09-07

    Readily available substituted phenols were coupled with pyruvate in buffer solution under atmospheric conditions to afford the corresponding para-vinylphenol derivatives while releasing only one molecule of CO2 and water as the by-products. This transformation was achieved by designing a biocatalytic system that combines three biocatalytic steps, namely the C-C coupling of phenol and pyruvate in the presence of ammonia, which leads to the corresponding tyrosine derivative, followed by deamination and decarboxylation. The biocatalytic transformation proceeded with high regioselectivity and afforded exclusively the desired para products. This method thus represents an environmentally friendly approach for the direct vinylation of readily available 2-, 3-, or 2,3-disubstituted phenols on preparative scale (0.5 mmol) that provides vinylphenols in high yields (65-83 %).

  10. General, mild, and intermolecular Ullmann-type synthesis of diaryl and alkyl aryl ethers catalyzed by diol-copper(I) complex.

    PubMed

    Naidu, Ajay B; Jaseer, E A; Sekar, Govindasamy

    2009-05-15

    A wide range of diaryl ethers and alkyl aryl ethers are synthesized through intermolecular C(aryl)-O bond formation from the corresponding aryl iodides/aryl bromides and phenols/alcohols through Ullmann-type coupling reaction in the presence of a catalytic amount of easily available (+/-)-diol L3-CuI complex under very mild reaction conditions. Less reactive aryl bromides can also be used for O-arylation of phenols under the same reaction conditions without increasing the reaction temperature, catalyst loading, and time. The catalytic system not only is capable of coupling hindered substrate but also tolerates a broad range of a series of functional groups.

  11. Phenolic compounds in Brassica vegetables.

    PubMed

    Cartea, María Elena; Francisco, Marta; Soengas, Pilar; Velasco, Pablo

    2010-12-30

    Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.

  12. Benzylic C-H trifluoromethylation of phenol derivatives.

    PubMed

    Egami, Hiromichi; Ide, Takafumi; Kawato, Yuji; Hamashima, Yoshitaka

    2015-12-04

    Phenol derivatives were trifluoromethylated using copper/Togni reagent. In dimethylformamide, the benzylic C-H bond at the para position of the hydroxyl group was selectively substituted with a CF3 group. In contrast, aromatic C-H trifluoromethylation occurred in alcoholic solvents. Practical utility of the reactions was demonstrated by application to the synthesis of a potent enoyl-acyl carrier protein reductase (FabI) inhibitor.

  13. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  14. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  15. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  16. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  17. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    EPA Science Inventory

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  18. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  19. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  20. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  1. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  2. 40 CFR 721.2825 - Alkyl ester (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl ester (generic name). 721.2825... Substances § 721.2825 Alkyl ester (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance alkyl ester (PMN P-84-968) is subject to reporting under this...

  3. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  4. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  5. 40 CFR 721.10233 - Linear alkyl epoxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Linear alkyl epoxide (generic). 721... Substances § 721.10233 Linear alkyl epoxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as linear alkyl epoxide (PMN...

  6. 40 CFR 721.4136 - Alkyl heteropolycyclic-aniline (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl heteropolycyclic-aniline... Specific Chemical Substances § 721.4136 Alkyl heteropolycyclic-aniline (generic). (a) Chemical substance... alkyl heteropolycyclic-aniline (PMN P-00-0067) is subject to reporting under this section for...

  7. 40 CFR 721.10699 - Polyfluorinated alkyl thio acrylamide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polyfluorinated alkyl thio acrylamide... Specific Chemical Substances § 721.10699 Polyfluorinated alkyl thio acrylamide (generic). (a) Chemical... as polyfluorinated alkyl thio acrylamide (PMN P-11-529) is subject to reporting under this...

  8. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  9. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  10. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  11. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  12. 40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salt. 721.2420 Section 721.2420 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2420 Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt. (a... generically as an alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject...

  13. 40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkyl sulfate salts. 721.2410 Section 721.2410 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a... generically as alkoxylated dialkyldiethylenetriamine, alkyl sulfate salts (PMN P-94-325, 326, and 327)...

  14. Copper-catalyzed radical carbooxygenation: alkylation and alkoxylation of styrenes.

    PubMed

    Liao, Zhixiong; Yi, Hong; Li, Zheng; Fan, Chao; Zhang, Xu; Liu, Jie; Deng, Zixin; Lei, Aiwen

    2015-01-01

    A simple copper-catalyzed direct radical carbooxygenation of styrenes is developed utilizing alkyl bromides as radical resources. This catalytic radical difunctionalization accomplishes both alkylation and alkoxylation of styrenes in one pot. A broad range of styrenes and alcohols are well tolerated in this transformation. The EPR experiment shows that alkyl halides could oxidize Cu(I) to Cu(II) in this transformation.

  15. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  16. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  17. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  18. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  19. 40 CFR 721.1878 - Alkali metal alkyl borohydride (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkali metal alkyl borohydride... Specific Chemical Substances § 721.1878 Alkali metal alkyl borohydride (generic). (a) Chemical substance... alkali metal alkyl borohydride (PMN P-00-1089) is subject to reporting under this section for...

  20. Poly(ethyleneoxide) functionalization through alkylation

    DOEpatents

    Sivanandan, Kulandaivelu; Eitouni, Hany Basam; Li, Yan; Pratt, Russell Clayton

    2015-04-21

    A new and efficient method of functionalizing high molecular weight polymers through alkylation using a metal amide base is described. This novel procedure can also be used to synthesize polymer-based macro-initiators containing radical initiating groups at the chain-ends for synthesis of block copolymers.

  1. 77 FR 72747 - Alkyl(C8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... Classification System (NAICS) codes is not intended to be exhaustive, but rather provides a guide to help readers.../reproductive screening test (OECD 422) toxicity study on a representative N- alkyl(C 8 -C 18... in the reproductive or developmental parameters examined. No systemic toxicity was observed in...

  2. Enantioselective Cyclopropanation with α-Alkyl-α-diazoesters Catalyzed by Chiral Oxazaborolidinium Ion: Total Synthesis of (+)-Hamavellone B.

    PubMed

    Shim, Su Yong; Kim, Jae Yeon; Nam, Miso; Hwang, Geum-Sook; Ryu, Do Hyun

    2016-01-15

    Chiral oxazaborolidinium ion-catalyzed asymmetric cyclopropanation of α- or α,β-substituted acroleins with α-alkyl-α-diazoesters has been developed. With this methodology, chiral functionalized cyclopropanes containing a quaternary stereogenic center were obtained with high to excellent enantioselectivities (up to >99% ee). The synthetic utility of optically enriched functionalized cyclopropane was demonstrated in the first total synthesis of (+)-hamavellone B, which establishes the absolute configuration of natural (+)-hamavellone B.

  3. Synthesis and structures of O-anthrylmethyl-substituted hexahomotrioxacalix[3]arenes

    NASA Astrophysics Data System (ADS)

    Jiang, Xue-Kai; Ikejiri, Yusuke; Ni, Xi-Long; Zeng, Xi; Redshaw, Carl; Yamato, Takehiko

    2016-09-01

    O-Alkylation of 7,15,23-tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix[3]arene (1H3) with 9-chloromethylanthracene 5 was carried out under different reaction conditions. Variation of the number of anthrylmethyl group introduced at the phenolic rim of hexahomotrioxacalix[3]arene 1H3 was achieved through selective O-alkylation using stoichiometric amounts of 9-chloromethylanthracene 5 in acetone to afford the mono-O-alkylated product 2H2An, the di-O-alkylated product 3HAn2 and the tri-O-alkylated product partial-cone-4An3, respectively. Interestingly, by using an acetone/benzene (1:1 v/v) mixed solvent system, the cone-4An3 was successfully synthesized. These results suggest that the solvent can also control the conformation of the O-alkylation products. The possible reaction routes of the cone-4An3 and partial-cone-4An3 are also discussed.

  4. Organocatalytic Enantioselective Synthesis of α-Hydroxyketones through a Friedel-Crafts Reaction of Naphthols and Activated Phenols with Aryl- and Alkylglyoxal Hydrates.

    PubMed

    Vila, Carlos; Quintero, Lucia; Blay, Gonzalo; Muñoz, M Carmen; Pedro, José R

    2016-11-04

    An efficient organocatalytic asymmetric synthesis of α-hydroxyketones has been developed. Quinine-derived thiourea catalyzed the enantioselective Friedel-Crafts alkylation of naphthols and activated phenols with aryl- and alkylglyoxal hydrates, providing the corresponding chiral α-hydroxyketones with high yields (up to 97%) and excellent enantioselectivities (up to 99% ee).

  5. [Phenolic foam prepared by lignin from a steam-explosion derived biorefinery of corn stalk].

    PubMed

    Wang, Guanhua; Chen, Hongzhang

    2014-06-01

    To increase the integral economic effectiveness, biorefineries of lignocellulosic materials should not only utilize carbohydrates hydrolyzed from cellulose and hemicellulose but also use lignin. We used steam-exploded corn stalk as raw materials and optimized the temperature and alkali concentration in the lignin extraction process to obtain lignin liquor with higher yield and purity. Then the concentrated lignin liquor was used directly to substitute phenol for phenolic foam preparation and the performances of phenolic foam were characterized by microscopic structure analysis, FTIR, compression strength and thermal conductivity detection. The results indicated that, when steam-exploded corn stalk was extracted at 120 degrees C for 2 h by 1% NaOH with a solid to liquid ratio of 1:10, the extraction yield of lignin was 79.67%. The phenolic foam prepared from the concentrated lignin liquor showed higher apparent density and compression strength with the increasing substitution rate of lignin liquor. However, there were not significant differences of thermal conductivity and flame retardant properties by the addition of lignin, which meant that the phenolic foam substituted by lignin liquor was approved for commercial application. This study, which uses alkali-extracted lignin liquor directly for phenolic foam preparation, provides a relatively simple way for utilization of lignin and finally increases the overall commercial operability ofa lignocellulosic biorefinery derived by steam explosion.

  6. Phenols from pyrolysis and co-pyrolysis of tobacco biomass components.

    PubMed

    Kibet, Joshua K; Khachatryan, Lavrent; Dellinger, Barry

    2015-11-01

    Phenol and its derivatives (phenol, o-, m-, p-cresols, catechol, hydroquinone, methoxy substituted phenols, etc. referred to as phenolic compounds or phenols) are well-known toxicants that exist in the environment and affect both human and natural ecosystems. This study explores quantitatively the yields of phenolic compounds from the thermal degradation (pyrolysis and oxidative pyrolysis) of common tobacco biomass components (lignin, tyrosine, ethyl cellulose, sodium alginate, and laminarin) as well as some mixtures (lignin/tyrosine, ethyl cellulose/tyrosine and sodium alginate/tyrosine) considered important in high temperature cooking, tobacco smoking, and forest fires. Special attention has been given to binary mixtures including those containing tyrosine-pyrolysis of binary mixtures of tyrosine with lignin and ethyl cellulose results in significant reductions in the yields of majority phenols relative to those from the thermal degradation of tyrosine. These results imply that the significant reductions of phenol yields in mixtures are not only dependent upon the mass fractions of the components but also the synergetic inhibition effect of biomass components on the thermal degradation of tyrosine. A mechanistic description of this phenomenon is suggested. The results may also be implied in tobacco industry that the cigarette paper (as ethyl cellulose derivative) may play a critical role in reducing the concentration of phenolic compounds released during tobacco burning.

  7. Effects of alkyl chain length on properties of 1-alkyl-3-methylimidazolium fluorohydrogenate ionic liquid crystals.

    PubMed

    Xu, Fei; Matsumoto, Kazuhiko; Hagiwara, Rika

    2010-11-15

    A series of 1-alkyl-3-methylimidazolium fluorohydrogenate salts (C(x)MIm(FH)(2)F, x=8, 10, 12, 14, 16, and 18) have been characterized by thermal analysis, polarized optical microscopy, IR spectroscopy, X-ray diffraction, and anisotropic ionic conductivity measurements. Liquid crystalline mesophases with a smectic A interdigitated bilayer structure are observed from C(10) to C(18), showing a fan-like or focal conic texture. The temperature range of the mesophase increases with the increase in the alkyl chain length (from 10.1 °C for C(10)MIm(FH)(2)F to 123.1 °C for C(18)MIm(FH)(2)F). The distance between the two layers in the smectic structure gradually increases with increasing alkyl chain length and decreases with increasing temperature. Conductivity parallel to the smectic layers is around 10 mS cm(-1) regardless of the alkyl chain length, whereas that perpendicular to the smectic layers decreases with increasing alkyl chain length because of the thicker insulating sheet with the longer alkyl chain.

  8. Quinolone antimicrobial agents. 1. Versatile new synthesis of 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids.

    PubMed

    Mitscher, L A; Gracey, H E; Clark, G W; Suzuki, T

    1978-05-01

    A flexible reaction sequence has been developed which starts with readily available anthranilic acids or isatoic anhydrides and leads regiospecifically to 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids after reaction with 1,3-dicarbonyl compounds. The sequence is superior to earlier published methods by allowing electron-releasing and -withdrawing groups in any position on the aro;atic ring, by allowing convenient substitution at C2, and better overall yield. A number of new and known antimicrobial agents were prepared and tested in vitro, demonstrating, inter alia, that substitution of the H at C2 abolished antibacterial activity.

  9. Preparation and characterization of phenol-formaldehyde adhesives modified with enzymatic hydrolysis lignin.

    PubMed

    Jin, Yanqiao; Cheng, Xiansu; Zheng, Zuanbin

    2010-03-01

    Phenol-formaldehyde (PF) adhesives modified with enzymatic hydrolysis lignin (EHL) were synthesized by a one-step process. The phenol component of the PF adhesives was partially substituted by EHL extracted from the residues of cornstalks used to produce bio-ethanol. The EHL-PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content, free formaldehyde content and brominable substance content of EHL-PF resins were investigated. The bonding strengths of the plywoods were determined, and the influences of the replacement percentage of phenol by EHL (a) and the NaOH content (b) on the properties of the adhesives were investigated. The results showed that the performance of the modified adhesives and the plywoods glued with them almost met the Chinese National Standard (GB/T 14732-2006) for first grade plywood when 20 wt% of the phenol was replaced by EHL.

  10. Changes in antioxidant activity and phenolic acid composition of tarhana with steel-cut oats.

    PubMed

    Kilci, A; Gocmen, D

    2014-02-15

    Steel-cut oats (SCO) was used to replace wheat flour in the tarhana formulation (control) at the levels of 10%, 20%, 30% and 40% (w/w). Control sample included no SCO. Substitution of wheat flour in tarhana formulation with SCO affected the mineral contents positively. SCO additions also increased phenolic acid contents of tarhana samples. The most abundant phenolic acids were ferulic and vanillic acids, followed by syringic acid in the samples with SCO. Tarhana samples with SCO also showed higher antioxidant activities than the control. Compared with the control, the total phenolic content increased when the level of SCO addition was increased. SCO addition did not have a deteriorative effect on sensory properties of tarhana samples and resulted in acceptable soup properties in terms of overall acceptability. SCO addition improved the nutritional and functional properties of tarhana by causing increases in antioxidant activity, phenolic content and phenolic acids.

  11. Pd(II)-catalyzed ortho- or meta-C-H olefination of phenol derivatives.

    PubMed

    Dai, Hui-Xiong; Li, Gang; Zhang, Xing-Guo; Stepan, Antonia F; Yu, Jin-Quan

    2013-05-22

    A combination of weakly coordinating auxiliaries and ligand acceleration allows for the development of both ortho- and meta-selective C-H olefination of phenol derivatives. These reactions demonstrate the feasibility of directing C-H functionalizations when functional groups are distal to target C-H bonds. The meta-C-H functionalization of electron-rich phenol derivatives is unprecedented and orthogonal to previous electrophilic substitution of phenols in terms of regioselectivity. These methods are also applied to functionalize α-phenoxyacetic acids, a fibrate class of drug scaffolds.

  12. Oxidation of phenols by horseradish peroxidase and lactoperoxidase compound II--kinetic considerations.

    PubMed

    Zahida, M S; Deva, W; Peerzada, G M; Behere, D V

    1998-12-01

    Oxidation of para substituted phenols by horseradish peroxidase compound II (HRP-II) and lactoperoxidase compound II (LPO-II) were studied using stopped flow technique. Apparent second order rate constants (kapp) of the reactions were determined. The kinetics of oxidation of phenols by HRP-II and LPO-II have been compared with the oxidation potentials of the substrates. Reorganization energies of electron-transfer of phenols to the enzymes were estimated from the variation of second order rate constants with the thermodynamic driving force.

  13. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.7770 Alkylphenoxypoly(oxyethylene) sulfuric acid...) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylphenoxypoly(oxyethylene)...

  14. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.7770 Alkylphenoxypoly(oxyethylene) sulfuric acid...) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylphenoxypoly(oxyethylene)...

  15. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.7770 Alkylphenoxypoly(oxyethylene) sulfuric acid...) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylphenoxypoly(oxyethylene)...

  16. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.7770 Alkylphenoxypoly(oxyethylene) sulfuric acid...) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylphenoxypoly(oxyethylene)...

  17. 40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.7770 Alkylphenoxypoly(oxyethylene) sulfuric acid...) The chemical substance identified as alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylphenoxypoly(oxyethylene)...

  18. Comparative study of the antioxidant activities of some lipase-catalyzed alkyl dihydrocaffeates synthesized in ionic liquid.

    PubMed

    Gholivand, Somayeh; Lasekan, Ola; Tan, Chin Ping; Abas, Faridah; Wei, Leong Sze

    2017-06-01

    The solubility limitations of phenolic acids in many lipidic environments are now greatly improved by their enzymatic esterification in ionic liquids (ILs). Herein, four different ILs were tested for the esterification of dihydrocaffeic acid with hexanol and the best IL was selected for the synthesis of four other n-alkyl esters with different chain-lengths. The effect of alkyl chain length on the anti-oxidative properties of the resulted purified esters was investigated using β-carotene bleaching (BCB) and free radical scavenging method DPPH and compared with butylated hydroxytoluene (BHT) as reference compound. All four esters (methyl, hexyl, dodecyl and octadecyl dihydrocaffeates) exhibited relatively strong radical scavenging abilities. The scavenging activity of the test compounds was in the following order: methyl ester>hexyl ester⩾dodecyl ester>octadecyl ester>BHT while the order for the BCB anti-oxidative activity was; BHT>octadecyl ester>dodecyl ester>hexyl ester>methyl ester.

  19. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1997-09-01

    The need to increase throughput in alkylation plants has resulted in higher operating temperatures and higher water levels in alkylation acids than projected by design. Combined with higher flow rates, the more severe process environment causes carbon steel to corrode at increased rates. Carbon steel is the main material of construction for horizontal contactors (Stratco reactors). A leak to the atmosphere in the hydraulic end cone of one contactor and the realization that basic corrosion data are not available for high throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in alkylation unit horizontal contactors is successfully mitigated by saturating fresh alkylation acid with ferrous sulfate.

  20. Searches for new alkylation catalysts, processes forge ahead

    SciTech Connect

    Rhodes, A.

    1994-08-22

    As a result of the hazardous properties of hydrofluoric acid (HF), HF alkylation has been the subject of much recent controversy. The safety and environmental requirements associated with the HF alkylation processes continue to drive industry to develop new alkylation technologies. In fact, several major process licensors are well on their ways to bringing these new technologies to market. The new alkylation processes under development center around new, less-harmful catalysts. Although this work is progressing rapidly, an update of the status of some of these new processes will keep refiners abreast of the new options they may soon have for building new alkylation units or retrofitting existing ones. The process development and economics are described for a Topsoe/Kellogg fixed bed alkylation process and the Kerr-McGee homogeneous alkylation technology process.

  1. Nucleophilic Aromatic Substitution.

    ERIC Educational Resources Information Center

    Avila, Walter B.; And Others

    1990-01-01

    Described is a microscale organic chemistry experiment which demonstrates one feasible route in preparing ortho-substituted benzoic acids and provides an example of nucleophilic aromatic substitution chemistry. Experimental procedures and instructor notes for this activity are provided. (CW)

  2. Olive oil phenols and neuroprotection.

    PubMed

    Khalatbary, Ali Reza

    2013-11-01

    Olive oil is a rich source of phenolic components which have a wide variety of beneficial health effects in vitro, in vivo, and clinically. The beneficial effects of olive oil phenols attributed to a variety of biological activities including free radical scavenging/antioxidant actions, anti-inflammatory effects, anti-carcinogenic properties, and anti-microbial activities. On the other hand, olive oil phenols have been shown to be some of neuroprotective effects against cerebral ischemia, spinal cord injury, Huntington's disease, Alzheimer's diseases, multiple sclerosis, Parkinson's disease, aging, and peripheral neuropathy. This paper summarizes current knowledge on the mechanisms of neuroprotective effects of olive oil phenols.

  3. Bio-activation of 4-alkyl analogs of 1,4-dihydropyridine mediated by cytochrome P450 enzymes.

    PubMed

    Li, Xiao-Xi; Zhang, Xiaoqian; Zheng, Qing-Chuan; Wang, Yong

    2015-06-01

    4-Alkyl-substituted 1,4-dihydropyridines (DHP) exhibit inhibitory activity toward certain cytochrome P450 enzymes (P450) during their biotransformation by these enzymes, which is called mechanism-based inactivation. Though much experimental evidence had proved the essentiality of alkyl radical for P450 inactivation, the underlying mechanism of such radical formation remains elusive. In the present study, density functional calculations were employed to investigate the dealkylation mechanism of 4-alkyl-substituted DHPs mediated by P450. Interestingly, our results indicate that the initial N-H activation proceeds via a proton-coupled electron transfer process, not via the long presumed hydrogen atom transfer mechanism or the stepwise electron transfer/proton transfer one, to form the amino radical and Cpd II complex. Subsequently, homolytic C-C bond cleavage at the 4-position occurs to afford the product complex involving an alkyl radical, an aromatic pyridine derivative. This C-C cleavage step is rate determining for the whole metabolic reaction, with an energy barrier of 7.9/7.9 kcal/mol on the quartet/doublet state, to which aromatization contributes as an essential intrinsic driving force. The 4-substituent groups induce differences in activation energy barriers and in the transition state structures of hydrogen abstraction process. The substrate reactivity correlates well with the stability of the generated alkyl radical as well as the C-C bond dissociation energy. Understanding the metabolic mechanism of DHP analogs is indeed essential for the related design of safer and more efficient drugs. Furthermore, our findings also enrich the mechanistic picture of amine oxidation catalyzed by P450.

  4. PROCESS FOR PRODUCING ALKYL ORTHOPHOSPHORIC ACID EXTRACTANTS

    DOEpatents

    Grinstead, R.R.

    1962-01-23

    A process is given for producing superior alkyl orthophosphoric acid extractants for use in solvent extraction methods to recover and purify various metals such as uranium and vanadium. The process comprises slurrying P/sub 2/O/ sub 5/ in a solvent diluent such as kerosene, benzene, isopropyl ether, and the like. An alipbatic alcohol having from nine to seventeen carbon atoms, and w- hcrein ihc OH group is situated inward of the terminal carbon atoms, is added to the slurry while the reaction temperature is mainiained below 60 deg C. The alcohol is added in the mole ratio of about 2 to l, alcohol to P/sub 2/O/sub 5/. A pyrophosphate reaotion product is formed in the slurry-alcohol mixture. Subsequently, the pyrophosphate reaction product is hydrolyzed with dilute mineral acid to produce the desired alkyl orthophosphoric aeid extractant. The extraetant may then be separated and utilized in metal-recovery, solvent- extraction processes. (AEC)

  5. Fatty acid alkyl esters: perspectives for production of alternative biofuels.

    PubMed

    Röttig, Annika; Wenning, Leonie; Bröker, Daniel; Steinbüchel, Alexander

    2010-02-01

    The global economy heads for a severe energy crisis: whereas the energy demand is going to rise, easily accessible sources of crude oil are expected to be depleted in only 10-20 years. Since a serious decline of oil supply and an associated collapse of the economy might be reality very soon, alternative energies and also biofuels that replace fossil fuels must be established. In addition, these alternatives should not further impair the environment and climate. About 90% of the biofuel market is currently captured by bioethanol and biodiesel. Biodiesel is composed of fatty acid alkyl esters (FAAE) and can be synthesized by chemical, enzymatic, or in vivo catalysis mainly from renewable resources. Biodiesel is already established as it is compatible with the existing fuel infrastructure, non-toxic, and has superior combustion characteristics than fossil diesel; and in 2008, the global production was 12.2 million tons. The biotechnological production of FAAE from low cost and abundant feedstocks like biomass will enable an appreciable substitution of petroleum diesel. To overcome high costs for immobilized enzymes, the in vivo synthesis of FAAE using bacteria represents a promising approach. This article points to the potential of different FAAE as alternative biofuels, e.g., by comparing their fuel properties. In addition to conventional production processes, this review presents natural and genetically engineered biological systems capable of in vivo FAAE synthesis.

  6. In pursuit of homoleptic actinide alkyl complexes.

    PubMed

    Seaman, Lani A; Walensky, Justin R; Wu, Guang; Hayton, Trevor W

    2013-04-01

    This Forum Article describes the pursuit of isolable homoleptic actinide alkyl complexes, starting with the pioneering work of Gilman during the Manhattan project. The initial reports in this area suggested that homoleptic uranium alkyls were too unstable to be isolated, but Wilkinson demonstrated that tractable uranium alkyls could be generated by purposeful "ate" complex formation, which serves to saturate the uranium coordination sphere and provide the complexes with greater kinetic stability. More recently, we reported the solid-state molecular structures of several homoleptic uranium alkyl complexes, including [Li(THF)4][U(CH2(t)Bu)5], [Li(TMEDA)]2[UMe6], [K(THF)]3[K(THF)2][U(CH2Ph)6]2, and [Li(THF)4][U(CH2SiMe3)6], by employing Wilkinson's strategy. Herein, we describe our attempts to extend this chemistry to thorium. The treatment of ThCl4(DME)2 with 5 equiv of LiCH2(t)Bu or LiCH2SiMe3 at -25 °C in THF affords [Th(CH2(t)Bu)5] (1) and [Li(DME)2][Th(CH2SiMe3)5 (2), respectively, in moderate yields. Similarly, the treatment of ThCl4(DME)2 with 6 equiv of K(CH2Ph) produces [K(THF)]2[Th(CH2Ph)6] (3), in good yield. Complexes 1-3 have been fully characterized, while the structures of 1 and 3 were confirmed by X-ray crystallography. Additionally, the electronic properties of 1 and 3 were explored by density functional theory.

  7. ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

    DOEpatents

    Long, R.L.

    1958-09-30

    A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

  8. [Antibacterial Activity of Alkylated and Acylated Derivatives of Low-Molecular Weight Chitosan].

    PubMed

    Shagdarova, B Ts; Il'ina, A V; Varlamov, V P

    2016-01-01

    A number of alkylated (quaternized) and acylated derivatives of low-molecular weight chitosan were obtained. The structure and composition of the compounds were confirmed by the results of IR and PMR spectroscopy, as well as conductometric titration. The effect of the acyl substituent and the degree of substitution of N-(2-hydroxy-3-trimethylammonium) with the propyl fragment appended to amino groups of the C2 atom of polymer chains on antibacterial activity against typical representatives of gram-positive and gram-negative microorganisms (Staphylococcus epidermidis and Escherichia coli) was studied. The highest activity was in the case of N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride with the maximal substitution (98%). The minimal inhibitory concentration of the derivative was 0.48 µg/mL and 3.90 µg/mL for S. epidermis and E. coli, respectively.

  9. The Scarlet Letter of Alkylation: A Mini Review of Selective Alkylating Agents

    PubMed Central

    Oronsky, Bryan T; Reid, Tony; Knox, Susan J; Scicinski, Jan J

    2012-01-01

    If there were a stigma scale for chemotherapy, alkylating agents would be ranked at the top of the list. The chemical term alkylation is associated with nonselective toxicity, an association that dates back to the use of nitrogen mustards during World War I as chemical warfare agents. That this stigma persists and extends to compounds that, through selectivity, attempt to “tame” the indiscriminate destructive potential of alkylation is the subject of this review. Selective alkylation, as it is referred to herein, constitutes an extremely nascent and dynamic field in oncology. The pharmacodynamic response to this selective strategy depends on a delicate kinetic balance between specificity and the rate and extent of binding. Three representative compounds are presented: RRx-001, 3-bromopyruvate, and TH-302. The main impetus for the development of these compounds has been the avoidance of the serious complications of traditional alkylating agents; therefore, it is the thesis of this review that they should not experience stigma by association. PMID:22937173

  10. Tetrahydrofurfuryloxide derivatives of alkyl aluminum species.

    SciTech Connect

    Boyle, Timothy J.; Avilucea, Gabriel; Bunge, Scott D.; Alam, Todd Michael; Rodriguez, Mark Andrew; Cherry, Brian Ray; Tissot, Ralph George, Jr.; Segall, Judith M.

    2004-12-01

    Tetrahydrofurfuryl alcohol (H-OTHF) was successfully reacted with a series of aluminum alkyls (AlR{sub 3}) to yield compounds of the general formula [R{sub 2}Al({mu}-OTHF)]{sub 2} where R = CH{sub 3} (1), CH{sub 2}CH{sub 3} (2), and CH{sub 2}CH(CH{sub 3}){sub 2} (3). Further, reactivity studies showed that the alkyls for 1 were easily exchanged, forming compounds of the general formula [Me(OR)Al({mu}-OTHF)]{sub 2} where OR = OC{sub 6}H{sub 3}(Me){sub 2}-2,6 (4), OC{sub 6}H{sub 3}(CMe{sub 3}){sub 2}-2,6 (5a), and OSi(C{sub 6}H5){sub 3} (6). For 5a, reflux temperatures were required to get the full exchange; otherwise the asymmetric derivative [Me(OR)Al({mu}-OTHF){sub 2}AlMe{sub 2}] (5b) was isolated. The bulk powders of 1-6 were found to be in agreement with the crystal structures on the basis of elemental analyses and multinuclear solid state NMR studies. Multinuclear solution state NMR studies indicate that the alkyl OTHF derivatives have cis/trans isomers due to the chiral proton on the OTHF ligand.

  11. Schistosomicidal Activity of Alkyl-phenols from the Cashew Anacardium occidentale against Schistosoma mansoni Adult Worms.

    PubMed

    Alvarenga, Tavane A; de Oliveira, Pollyanna F; de Souza, Julia M; Tavares, Denise C; Andrade E Silva, Márcio L; Cunha, Wilson R; Groppo, Milton; Januário, Ana H; Magalhães, Lizandra G; Pauletti, Patrícia M

    2016-11-23

    Bioassay-guided study of the ethanol extract from the cashew Anacardium occidentale furnished cardol triene (1), cardol diene (2), anacardic acid triene (3), cardol monoene (4), anacardic acid diene (5), 2-methylcardol triene (6), and 2-methylcardol diene (7). 1D- and 2D-NMR experiments and HRMS analysis confirmed the structures of compounds 1-7. Compounds 2 and 7 were active against Schistosoma mansoni adult worms in vitro, with LC50 values of 32.2 and 14.5 μM and selectivity indices of 6.1 and 21.2, respectively. Scanning electron microscopy of the tegument of male worms in the presence of compound 7 at 25 μM after 24 h of incubation showed severe damage as well as peeling and reduction in the number of spine tubercles. Transmission electron microscopy analyses revealed swollen mitochondrial membrane, vacuoles, and altered tegument in worms incubated with compound 2 (25 μM after 24 h). Worms incubated with compound 7 (25 μM after 24 h) had lysed interstitial tissue, degenerated mitochondria, and drastically altered tegument. Together, the results indicated that compound 7 presents promising in vitro schistosomicidal activity.

  12. Monitoring Alkyl Phenol Ethoxylates And Degradation Products After Land Application Of Anaerobically Digested Biosolids

    EPA Science Inventory

    Annually, over 3 million dry tons of treated sewage sludge (or biosolids) are applied on agricultural lands in the U.S. In 2002, the National Research Council (NRC) recommended an examination of biosolids management practices including chemicals such as surfactants used in clean...

  13. MONITORING MICROBES, ALKYL PHENOLS, AND SOIL TOXICITY AFTER LAND APPLICATION OF ANAEROBICALLY DIGESTED BIOSOLIDS

    EPA Science Inventory

    A common disposal practice for municipal biosolids is to spread this material on agricultural fields as a soil amendment. For example, over 3 million dry tons of treated sewage sludge (or biosolids) are applied on agricultural lands in the US. The regulations which govern the lan...

  14. Zero-valent iron-activated persulfate oxidation of a commercial alkyl phenol polyethoxylate.

    PubMed

    Temiz, Kubra; Olmez-Hanci, Tugba; Arslan-Alaton, Idil

    2016-01-01

    Aqueous Triton X-45 (TX-45; 20 mg/L; original total organic carbon (TOC) = 14 mg/L), a representative, commercially important alkylphenol polyethoxylate, was subjected to persulfate (PS) oxidation activated with zero-valent iron (ZVI) nanoparticles. After optimization of the ZVI/PS treatment combination (1 g/L ZVI; 2.5 mM PS at pH5) in terms of pH (3-9), ZVI (0.5-5 g/L) and PS (0.5-5.0 mM) concentrations, TX-45 could be efficiently (>90%) degraded within short treatment periods (<60 min) accompanied with significant (>40%) TOC removals. The degree of PS consumption and Fe release was also followed during the experiments and a positive correlation existed between enhanced TX-45 removals and ZVI-activated PS consumption rates accompanied with a parallel Fe release. Acute toxicity tests were conducted using two different bioassays to examine the toxicological safety of the ZVI/PS oxidation system. Acute toxicity profiles significantly decreased from an original value of 66% relative inhibition to 21% and from 16% relative inhibition to non-toxic values according to Vibrio fischeri and Pseudokirchneriella subcapitata bioassays, respectively. The photobacterium V. fischeri appeared to be more sensitive to TX-45 and its degradation products than the microalgae P. subcapitata.

  15. Secondary organic aerosol production from aqueous reactions of atmospheric phenols with an organic triplet excited state.

    PubMed

    Smith, Jeremy D; Sio, Vicky; Yu, Lu; Zhang, Qi; Anastasio, Cort

    2014-01-21

    Condensed-phase chemistry plays a significant role in the formation and evolution of atmospheric organic aerosols. Past studies of the aqueous photoformation of secondary organic aerosol (SOA) have largely focused on hydroxyl radical oxidation, but here we show that triplet excited states of organic compounds ((3)C*) can also be important aqueous oxidants. We studied the aqueous photoreactions of three phenols (phenol, guaiacol, and syringol) with the aromatic carbonyl 3,4-dimethoxybenzaldehyde (DMB); all of these species are emitted by biomass burning. Under simulated sunlight, DMB forms a triplet excited state that rapidly oxidizes phenols to form low-volatility SOA. Rate constants for these reactions are fast and increase with decreasing pH and increasing methoxy substitution of the phenols. Mass yields of aqueous SOA are near 100% for all three phenols. For typical ambient conditions in areas with biomass combustion, the aqueous oxidation of phenols by (3)C* is faster than by hydroxyl radical, although rates depend strongly on pH, oxidant concentrations, and the identity of the phenol. Our results suggest that (3)C* can be the dominant aqueous oxidant of phenols in areas impacted by biomass combustion and that this is a significant pathway for forming SOA.

  16. Syntheses and antimalarial activities of N-substituted 11-azaartemisinins.

    PubMed

    Torok, D S; Ziffer, H; Meshnick, S R; Pan, X Q; Ager, A

    1995-12-22

    A two-step reaction sequence between artemisinin and methanolic ammonia followed by treatment with Amberlyst 15 yielded 11-azaartemisinin in 65% yield. Substituting a variety of primary alkyl- and heteroaromatic amines for ammonia in the reaction sequence yields N-substituted 11-azaartemisinins in similar or greater yield. When Amberlyst 15 is replaced by a mixture of sulfuric acid/silica gel, both 11-azaartemisinin and the expected metabolite, 10-azadesoxyartemisinin, are formed in 45% and 15% yields, respectively. In vitro and in vivo test data for a number of novel N-substituted 11-azaartemisinins, against drug-resistant strains of Plasmodium falciparum, show they possess antimalarial activities equal to or greater than that of artemisinin. The most active derivative, N-(2'-acetaldehydo)-11-azaartemisinin, 17, was 26 times more active in vitro and 4 times more active in vivo than artemisinin.

  17. Iron-catalyzed, microwave-promoted, one-pot synthesis of 9-substituted xanthenes by a cascade benzylation-cyclization process.

    PubMed

    Xu, Xiaobing; Xu, Xiaolei; Li, Hongfeng; Xie, Xin; Li, Yanzhong

    2010-01-01

    An efficient iron-catalyzed, microwave-promoted cascade benzylation-cyclization of phenols is reported. Benzyl acetates, benzyl bromides, and benzyl carbonates are suitable benzylating reagents. The reactions proceed to afford both 9-aryl and 9-alkyl xanthene derivatives in good to high yields using FeCl(3) as the catalyst under MW irradiation conditions.

  18. Synthesis, nematocidal activity and SAR study of novel difluoromethylpyrazole carboxamide derivatives containing flexible alkyl chain moieties.

    PubMed

    Liu, Xing-Hai; Zhao, Wen; Shen, Zhong-Hua; Xing, Jia-Hua; Xu, Tian-Ming; Peng, Wei-Li

    2017-01-05

    A series of novel difluoromethylpyrazole carboxamides derivatives were synthesized by introduction of flexible alkyl chain. Nematicidal bioassay results showed that some of them exhibited good control efficacy against M. incognita, which indicated that these difluoromethylpyrazole carboxamides derivatives might be potential novel lead compounds for discovery new nematicides. The nematicidal activity was affected by the substituted position in the molecule, especially the substitution group on the alkyl chain. It was found that the compound 6-9 and 6-23 possess about 50% inhibition effect against M. incognita even at 5.0 and 1.0 mg L(-1). Meanwhile, greenhouse field trial showed the nematicidal activity of compound 6-9 is a litter weaker than that of Abamectin. The mammalian toxicology results indicated that compound 6-9 was a low-toxicity and low-sensitive compound. In conclusion compound 6-9 is a potential candidate for further development. In addition, the molecular docking simulations revealed that compounds 6 with a flexible NHCOO show its binding affinities for the acetylcholine receptor (AChR), which may provide useful information for further design novel nematicides.

  19. Peroxidase catalyzed polymerization of phenol

    SciTech Connect

    Vasudevan, P.T.; Li, L.O.

    1996-07-01

    The effect of horseradish peroxidase (HRP) and H{sub 2}O{sub 2} concentrations on the removal efficiency of phenol, defined as the percentage of phenol removed from solution as a function of time, has been investigated. When phenol and H{sub 2}O{sub 2} react with an approximately one-to-one stoichiometry, the phenol is almost completely precipitated within 10 min. The reaction is inhibited at higher concentrations of H{sub 2}O{sub 2}. The removal efficiency increases with an increase in the concentration of HRP, but an increase in the time of treatment cannot be used to offset the reduction in removal efficiency at low concentrations of the enzyme, because of inactivation of the enzyme. One molecule of HRP is needed to remove approximately 1100 molecules of phenol when the reaction is conducted at pH 8.0 and at ambient temperature. 9 refs., 5 figs.

  20. DNA-directed alkylating ligands as potential antitumor agents: sequence specificity of alkylation by intercalating aniline mustards.

    PubMed

    Prakash, A S; Denny, W A; Gourdie, T A; Valu, K K; Woodgate, P D; Wakelin, L P

    1990-10-23

    The sequence preferences for alkylation of a series of novel parasubstituted aniline mustards linked to the DNA-intercalating chromophore 9-aminoacridine by an alkyl chain of variable length were studied by using procedures analogous to Maxam-Gilbert reactions. The compounds alkylate DNA at both guanine and adenine sites. For mustards linked to the acridine by a short alkyl chain through a para O- or S-link group, 5'-GT sequences are the most preferred sites at which N7-guanine alkylation occurs. For analogues with longer chain lengths, the preference of 5'-GT sequences diminishes in favor of N7-adenine alkylation at the complementary 5'-AC sequence. Magnesium ions are shown to selectively inhibit alkylation at the N7 of adenine (in the major groove) by these compounds but not the alkylation at the N3 of adenine (in the minor groove) by the antitumor antibiotic CC-1065. Effects of chromophore variation were also studied by using aniline mustards linked to quinazoline and sterically hindered tert-butyl-9-aminoacridine chromophores. The results demonstrate that in this series of DNA-directed mustards the noncovalent interactions of the carrier chromophores with DNA significantly modify the sequence selectivity of alkylation by the mustard. Relationships between the DNA alkylation patterns of these compounds and their biological activities are discussed.

  1. Effects of alkyl parabens on plant pathogenic fungi.

    PubMed

    Ito, Shinsaku; Yazawa, Satoru; Nakagawa, Yasutaka; Sasaki, Yasuyuki; Yajima, Shunsuke

    2015-04-15

    Alkyl parabens are used as antimicrobial preservatives in cosmetics, food, and pharmaceutical products. However, the mode of action of these chemicals has not been assessed thoroughly. In this study, we determined the effects of alkyl parabens on plant pathogenic fungi. All the fungi tested, were susceptible to parabens. The effect of linear alkyl parabens on plant pathogenic fungi was related to the length of the alkyl chain. In addition, the antifungal activity was correlated with the paraben-induced inhibition of oxygen consumption. The antifungal activity of linear alkyl parabens likely originates, at least in part, from their ability to inhibit the membrane respiratory chain, especially mitochondrial complex II. Additionally, we determined that some alkyl parabens inhibit Alternaria brassicicola infection of cabbage.

  2. Alkylation damage by lipid electrophiles targets functional protein systems.

    PubMed

    Codreanu, Simona G; Ullery, Jody C; Zhu, Jing; Tallman, Keri A; Beavers, William N; Porter, Ned A; Marnett, Lawrence J; Zhang, Bing; Liebler, Daniel C

    2014-03-01

    Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells treated with lipid electrophile probes. Protein target profiles revealed three damage susceptibility classes, as well as proteins that were highly resistant to alkylation. Damage occurred selectively across functional protein interaction networks, with the most highly alkylation-susceptible proteins mapping to networks involved in cytoskeletal regulation. Proteins with lower damage susceptibility mapped to networks involved in protein synthesis and turnover and were alkylated only at electrophile concentrations that caused significant toxicity. Hierarchical susceptibility of proteome systems to alkylation may allow cells to survive sublethal damage while protecting critical cell functions.

  3. 4'-[Aminomethyl]fluorescein and its N-alkyl derivatives: useful reagents in immunodiagnostic techniques.

    PubMed

    Shipchandler, M T; Fino, J R; Klein, L D; Kirkemo, C L

    1987-04-01

    A new class of fluorescein derivatives with chemically reactive amino and N-alkylamino "arms" in the 4'-position were synthesized and their utility in the development of fluorescence polarization immunoassays (FPIA) for cortisol and estriol was evaluated. The positioning of the arm in one of the phenolic rings introduced chirality due to hindered rotation and led to rotational isomers. These were separable when brought into a chiral environment, i.e., conjugated to steroid molecules. In the case of cortisol conjugates, the rotamers had similar properties in the FPIA. In the case of estriol conjugates, however, each rotamer exhibited different immunoassay characteristics. The rotamers interconverted at 80 degrees C, with the rate increasing with temperature. An unusual N-alkylation phenomenon by alkanols in acidic medium was observed. A serum cortisol FPIA, developed using an N-alkylamino fluorescein derivative, showed good correlation with a reference RIA.

  4. Nucleophilic selectivity of alkylating agents and their hypermutability in Drosophila as predictors of carcinogenic potency in rodents.

    PubMed

    Vogel, E W; Barbin, A; Nivard, M J; Bartsch, H

    1990-12-01

    The nucleophilic selectivity (Swain-Scott s constant or initial 7-alkylguanine/O6-alkylguanine ratio in DNA) of 60 alkylating agents, mostly monofunctional or cross-linking was compared to their carcinogenic potency in rodents (median TD50 estimates) and to two genotoxicity indices in Drosophila: (i) hypermutability, measured by the increased frequency of induced sex-linked recessive lethal mutations (SLRL) in a strain defective in DNA excision repair (exr-), as compared to the wild-type (exr+); (ii) relative clastogenic efficiency, expressed by the ratio of chromosomal aberrations (ring-X loss) to SLRL determined in the exr+ strain. For a subset of direct-acting, monofunctional alkylating agents, nucleophilic selectivity and TD50 values or hypermutability indices were linearly correlated. In addition, the hypermutability indices in Drosophila by methylating or ethylating procarcinogens were similar to the corresponding values of their ultimate metabolites. In contrast, cross-linking agents, including antitumour drugs, did not show these positive correlations. The relative clastogenic efficiencies in Drosophila of 26 direct-acting, alkylating carcinogens increased with both their cross-linking activity and nucleophilic selectivity. By analyzing mutational spectra in Drosophila induced in the vermilion gene by four monofunctional alkylating agents with contrasting s values, critical DNA lesions, i.e. type of base pair substitution mutations, deletions, insertions, involved in genotoxicity were pinpointed. Thus, these multi-endpoint analyses should, as a new approach, assist in the quantitative risk evaluation of genotoxic agents.

  5. Polymeric foams stable at high temperatures

    NASA Technical Reports Server (NTRS)

    Riccitiello, S. R.; Harrison, E. S.; Delano, C. B.

    1976-01-01

    Crosslinked poly(N-arylenebenzimidazoles) are stable up to 370 C. Polymers are made by mixing appropriate stoichiometric amounts of tetramine and aromatic dicarboxylic acid anhydride with phenol or alkyl-substituted phenol.

  6. Lithium perchlorate-nitromethane-promoted alkylation of anilines with arylmethanols.

    PubMed

    Zhou, Jun; Mao, Hai-Feng; Wang, Lu; Zou, Jian-Ping; Zhang, Wei

    2011-11-01

    A new application of lithium perchlorate-nitromethane (LPNM) for the formation of aromatic C-N and C-C bonds is introduced. LPNM-promoted reactions of anilines with diarylmethanols selectively generate N-alkylated anilines or mono and double Friedel-Crafts alkylation products under different conditions by changing the reaction time, reaction temperature, and the ratio of the reactants. This method does not require the use of transition metal catalysts to prepare alkylated aniline derivatives.

  7. Corrosion abatement in sulfuric acid alkylation unit horizontal contactors

    SciTech Connect

    Schutt, H.U.

    1999-03-01

    A leak to the atmosphere in the hydraulic end cone of a horizontal contactor and the realization that basic corrosion data are not available for high-throughput process conditions in alkylation units prompted a laboratory study to develop the lacking expertise. Corrosion in the horizontal contractor of an alkylation unit was mitigated successfully by saturating fresh alkylation acid with ferrous sulfate (FeSO{sub 4}).

  8. Photochemical Production of Alkyl Nitrates in the Tropical Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Dahl, E. E.; Yvon-Lewis, S. A.; Saltzman, E. S.

    2005-12-01

    Alkyl nitrates are important to the tropospheric NOx/ozone cycle because they represent a significant fraction of the reactive nitrogen (NOy). Previous work has shown that there is an oceanic source of alkyl nitrates. A photochemical mechanism for the formation of alkyl nitrates in seawater has been proposed. This mechanism involves the reaction of ROO and NO, where ROO is an alkyl peroxy radical. ROO and NO radicals in seawater are derived from the photolysis of DOM and nitrite, respectively. In this study, the photochemical production of low molecular weight alkyl nitrates (C1-C3) was observed in shipboard incubation experiments in the tropical Pacific during the PHASE 1 cruise. Seawater samples from several regions, including high and low-chlorophyll areas, were collected and incubated. Alkyl nitrate production rates as high as 2 nM/hour were observed. The production rate of alkyl nitrates was clearly dependent upon the initial concentration of nitrite, most likely as the source for NO radicals. While the magnitude of production varied between sample locations, the ratios of the production rates of the various alkyl nitrates remained relatively constant. The observed production ratios of methyl, ethyl, isopropyl, and n-propyl nitrate were 5.9:1.0:0.1:0.2. These ratios presumably reflect the speciation of peroxy radicals formed in seawater, and the yield of alkyl nitrates from the ROO+NO reaction. The observed production rate ratios are similar to the concentration ratios of alkyl nitrates observed in ambient seawater and the overlying atmosphere during the study. A comparison of the measured production rates and the observed concentrations, suggests that photochemically produced alkyl nitrates are a major source of atmospheric alkyl nitrates in the surface ocean and marine atmosphere.

  9. Evaluation of the phototoxicity of unsubstituted and alkylated polycyclic aromatic hydrocarbons to mysid shrimp (Americamysis bahia): Validation of predictive models.

    PubMed

    Finch, Bryson E; Marzooghi, Solmaz; Toro, Dominic M Di; Stubblefield, William A

    2017-01-06

    Crude oils are composed of an assortment of hydrocarbons, some of which are polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are of particular interest due to their narcotic and potential phototoxic effects. Several studies have examined the phototoxicity of individual PAHs and fresh and weathered crude oils, and several models have been developed to predict PAH toxicity. Fingerprint analyses of oils have shown that PAHs in crude oils are predominantly alkylated. However, current models for estimating PAH phototoxicity assume toxic equivalence between unsubstituted (i.e., parent) and alkyl-substituted compounds. This approach may be incorrect if substantial differences in toxic potency exist between unsubstituted and substituted PAHs. The objective of the present study was to examine the narcotic and photo-enhanced toxicity of commercially available unsubstituted and alkylated PAHs to mysid shrimp (Americamysis bahia). Data were used to validate predictive models of phototoxicity based on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap approach and to develop relative effect potencies. Results demonstrated that photo-enhanced toxicity increased with increasing methylation and that phototoxic PAH potencies vary significantly among unsubstituted compounds. Overall, predictive models based on the HOMO-LUMO gap were relatively accurate in predicting phototoxicity for unsubstituted PAHs but are limited to qualitative assessments. Environ Toxicol Chem 2017;9999:1-7. © 2017 SETAC.

  10. Triazolium based ionic liquid crystals: Effect of asymmetric substitution

    SciTech Connect

    Stappert, K.; Mudring, A. -V.

    2015-01-27

    A new series of ten different asymmetrical 1-dodecyl-3-alkyl-triazolium bromides, [C12CnTr][Br], has been synthesized and their mesomorphic behavior studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). The influence of the chain length of the triazolium salts is investigated to explore the effect of asymmetric substitution on the phase behaviour of these compounds. For that reason, the length of one alkyl chain was varied from 14 to 1 carbon atoms (n = 14, 12, 10, 8–4, 2, 1) while the other alkyl chain was kept at 12 carbon. Single crystal X-ray structure analysis of compounds [C12C12Tr][Br] and [C12C5Tr][Br] reveal that the cations adopt a U-shaped conformation with head-to-head arranged triazolium cores. In contrast, for [C12C1Tr][Br], a rod like shape of the cation with interdigitated alkyl chains is found. All investigated compounds are thermotropic liquid crystals. Higher ordered smectic phases, smectic C as well as smectic A phases were found depending on the chain length of the cation. Moreover, the clearing point temperature decreases with decreasing chain length with exception for the n-dodecyl-3-alkyltrizoliumbromides with the two shortest alkyl chains, [C12C2Tr][Br] and [C12C1Tr][Br], which present higher clearing temperatures (86 and 156 °C) and are structurally distinctly different.

  11. Triazolium based ionic liquid crystals: Effect of asymmetric substitution

    DOE PAGES

    Stappert, K.; Mudring, A. -V.

    2015-01-27

    A new series of ten different asymmetrical 1-dodecyl-3-alkyl-triazolium bromides, [C12CnTr][Br], has been synthesized and their mesomorphic behavior studied by DSC (differential scanning calorimetry), POM (polarizing optical microscopy) and SAXS (small angle X-ray scattering). The influence of the chain length of the triazolium salts is investigated to explore the effect of asymmetric substitution on the phase behaviour of these compounds. For that reason, the length of one alkyl chain was varied from 14 to 1 carbon atoms (n = 14, 12, 10, 8–4, 2, 1) while the other alkyl chain was kept at 12 carbon. Single crystal X-ray structure analysis ofmore » compounds [C12C12Tr][Br] and [C12C5Tr][Br] reveal that the cations adopt a U-shaped conformation with head-to-head arranged triazolium cores. In contrast, for [C12C1Tr][Br], a rod like shape of the cation with interdigitated alkyl chains is found. All investigated compounds are thermotropic liquid crystals. Higher ordered smectic phases, smectic C as well as smectic A phases were found depending on the chain length of the cation. Moreover, the clearing point temperature decreases with decreasing chain length with exception for the n-dodecyl-3-alkyltrizoliumbromides with the two shortest alkyl chains, [C12C2Tr][Br] and [C12C1Tr][Br], which present higher clearing temperatures (86 and 156 °C) and are structurally distinctly different.« less

  12. Alkyl Chlorides as Hydrogen Bond Acceptors

    SciTech Connect

    Nadas, Janos I; Vukovic, Sinisa; Hay, Benjamin

    2012-01-01

    To gain an understanding of the role of an alkyl chloride as a hydrogen bond acceptor, geometries and interaction energies were calculated at the MP2/aug-cc-pVDZ level of theory for complexes between ethyl chloride and representative hydrogen donor groups. The results establish that these donors, which include hydrogen cyanide, methanol, nitrobenzene, pyrrole, acetamide, and N-methylurea, form X-H {hor_ellipsis} Cl hydrogen bonds (X = C, N, O) of weak to moderate strength, with {Delta}E values ranging from -2.8 to -5.3 kcal/mol.

  13. Lower-Rim Substituted Calixarenes and Their Applications

    PubMed Central

    Jose, Princy; Menon, Shobana

    2007-01-01

    This review discusses in detail “calixarenes” since their discovery as by-products of the phenol formaldehyde bakelites till the present scenario wherein calixarene has assumed a new dimension in the field of supramolecular chemistry. Extensive literature exists for calixarenes; but herein we have tried to concentrate on the different lower-rim modified calixarenes with their potential applications. An attempt has also been made to critically evaluate the synthesis procedures for different lower-rim substituted calixarenes. PMID:17611612

  14. Phenol Analysis -- Some Analytical Considerations

    NASA Technical Reports Server (NTRS)

    Starkey, R. J., Jr.

    1971-01-01

    Contamination of potable water supplies with halogenated phenols in concentrations of 2-10 parts per billion (ppb) produces objectionable tastes and odors capable of influencing consumer acceptability. Routine analysis by the distillation/ 4-aminoantipyrine method is limited by lack of sensitivity and subject to interference by aryl amines. This has been overcome by developing a continuous liquid-liquid extraction system to selectively isolate phenols and eliminate major interfering substances. Stable reagents have been formulated to reduce blank color and extend sensitivity. Equipment suitable for analysis of phenols at the 1 ppb level or less in 20 minutes is described.

  15. Determination of reaction rate constants for alkylation of 4-(p-nitrobenzyl) pyridine by different alkylating agents.

    PubMed

    Walles, S A

    1980-02-01

    The rate constants have been determined for the reaction between some different alkylating agents and 4-(p-nitrobenzyl) pyridine (NBP) in methanol. These constants have been compared with those for alkylation of aniline in water. All the constants were lower in methanol than in water but in different degrees. The rate constants of the different alkylating agents have been calculated at a nucleophilic strength n=2. The genetic risk defined as the degree of alkylation of a nucleophile (n=2) is equivalent to the rate constant kn=2 and the target dose. The dependence of the genetic risk on the rate constant (kn=2) is discussed.

  16. Substituted androstanes as aromatase inhibitors

    NASA Astrophysics Data System (ADS)

    Levina, Inna S.

    1998-11-01

    The synthesis and structure-activity relationships of inhibitors of steroid aromatase which catalyses the last stage of a multistep biotransformation of cholesterol into estrogens, viz., aromatisation of C19-steroids into C18-phenolic steroids, are discussed. Compounds of the androstane series which are structurally related to the natural substrate, viz., androst-4-ene-3,17-dione, are the subjects of consideration. The review encompasses problems of synthesis of various substituted androstanes and their aromatase-inhibiting activities and structural requirements for selective specific aromatase inhibitors based on in vitro and in vivo structure-activity studies of compounds synthesised, their biological properties and the results of clinical trials. Special attention is paid to practical applications of aromatase inhibitors in the treatment of hormone-dependent mammary and ovarian tumours as well as benign prostatic tumours. In writing this report, the author has used all the information currently available in the chemical, biochemical, endocrinological and medicinal literature as well as in patents. The bibliography includes 173 references.

  17. Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

    DOEpatents

    Alvarez, Marc A.; Martinez, Rodolfo A.; Unkefer, Clifford J.

    2010-02-16

    The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group.

  18. Amino phenol-detergent/dispersant combinations and fuels and lubricants containing same

    SciTech Connect

    Clason, D.L.; Cohen, J.M.; Pindar, J.F.

    1980-04-29

    Disclosed are combinations of amino phenols, wherein said phenols contain a substantially saturated hydrocarbon substituent of at least 10 aliphatic carbon atoms, and one or more detergent/dispersants selected from the group consisting of (I) neutral or basic metal salts of an organic sulfur acid, phenol or carboxylic acid; (II) hydrocarbyl-substituted amines wherein the hydrocarbyl substituent is substantially aliphatic and contains at least 12 carbon atoms; (III) acylated nitrogen-containing compounds having a substituent of at least 10 aliphatic carbon atoms; and (IV) nitrogen-containing condensates of a phenol, aldehyde and amino compound. Fuels and lubricants containing such combinations as additives are particularly useful in two-cycle (two-stroke) engines.

  19. Review of various treatment methods for the abatement of phenolic compounds from wastewater.

    PubMed

    Girish, C R; Murty, V Ramachandra

    2012-04-01

    Phenol and its derivatives are considered among the most hazardous organic pollutants from industrial wastewater and they are toxic even at low concentrations. Besides the existence of phenol in natural water source it can lead to the formation of other toxic substituted compounds. So this has led to growing concern on setting up of rigid limits on the acceptable level of phenol in the environment. The various methods for the treatment of phenol from wastewater streams are briefly reviewed. The various technologies like distillation, liquid-liquid extraction with different solvents, adsorption over activated carbons and polymeric and inorganic adsorbents, membrane pervaporation and membrane-solvent extraction, have been elucidated. The advantages and disadvantages of the various methods are illustrated and their performances are compared.

  20. Phenolic acid-based poly(anhydride-esters) as antioxidant biomaterialsa

    PubMed Central

    Prudencio, Almudena; Faig, Jonathan J.; Song, MinJung

    2015-01-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic acids. Further, the released phenolic acids were found to maintain antioxidant potency relative to free phenolic acid controls as determined by a 2,2-diphenyl-1-picrylhydrazyl assay. Polymer cytotoxicity was assessed with L929 fibroblasts in polymer-containing media; appropriate cell morphology and high fibroblast proliferation were obtained for the polymers at the lower concentrations. These polymers deliver non-cytotoxic levels of naturally occurring antioxidants, which could be efficacious in topical delivery of antioxidant therapies. PMID:26425923