Oxygen In Acetic Acid Research Articles

Production of NMSBA from the oxidation of NMST in the homogeneous Co/Mn/Br/H3PMoxW12−xO40 catalytic system

Abstract2‐nitro‐4‐methylsulphonylbenzoic acid (NMSBA) is an important intermediate for the preparation of the highly effective herbicide mesotrione. NMSBA is produced from the oxidation of 2‐nitro‐4‐ methylsulphonyltoluene (NMST) by nitric acid commercially, which suffers from the serious problems of low yield and heavy pollution. In this paper, a homogeneous system consisting of Co/Mn/Br/ · H3PMoxW12−xO40 has been applied to catalyze the production of NMSBA by oxidizing NMST with oxygen in acetic acid. The experiments indicate that the best value of x in the phosphomolybdenum tungsten heteropoly acid is 3. The optimum composition of this catalyst system is 1163 ppm H3Pmo3W9O40 · 12.17H2O, 247.5 ppm Co, 453.5 ppm Mn, and 1075 ppm Br. Such a catalytic system is able to achieve a NMST conversion of 94.93% and a NMSBA selectivity of 99.84%. H3PMo3W9O40 exceeds both H3PMo12O40 and H3PW12O40 as a catalyst in the production of NMSBA from the oxidation of NMST by oxygen.

Effect of Competitive Adsorbates on the Catalytic Activity of H3PMo12O40@C in the Oxidation of NMST to NMSBA

AbstractThe effect of competitive adsorption on the catalytic performance of H3PMo12O40@C catalyst for producing 2-nitro-4-methylsulfonylbenzoic acid (NMSBA) from the oxidation of 2-nitro-4- methylsulfonyltoluene (NMST) by oxygen in acetic acid has been investigated. Six kinds of acids were added into the impregnation solution as competitive adsorbates for phosphomolybdic acid in the preparation of H3PMo12O40@C catalyst. H2SO4, HCl, HNO3, CH3COOH and H2C2O4 are beneficial to improving the catalytic activity of the H3PMo12O40@C catalyst. The corresponding optimum impregnation concentrations for H2SO4, HCl, HNO3, CH3COOH and H2C2O4 are 0.4, 0.3, 0.3, 1.0 and 0.3 mol L−1, respectively. The addition of H3PO4 exerts a negative effect on the catalytic capability of H3PMo12O40@C catalyst. The results of TEM characterization show that good dispersion of H3PMo12O40 on the surface of the H3PMo12O40@C catalyst is beneficial to ameliorating the catalytic ability of H3PMo12O40@C catalyst in the production of NMSBA from NMST by oxygen in acetic acid. The results of NH3-TPD indicate that the acidity of the H3PMo12O40@C also favors the improvement of the catalytic capability of H3PMo12O40@C in the oxidation of NMST to NMSBA.

ChemInform Abstract: Organocatalytic Aerobic Oxidation of α‐Fluoroalkyl Alcohols to Fluoroalkyl Ketones at Room Temperature.

The organocatalytic aerobic oxidation of electron-deficient α-fluoroalkyl alcohols at room temperature is described. The resulting fluoroalkyl ketones are versatile synthetic intermediates for a variety of fluorine-containing molecules. This otherwise difficult transformation has now been accomplished by the reaction of α-fluoroalkyl alcohols with N-oxyl radicals, catalytically generated from 9-azabicyclo[3.3.1]nonan-3-one N-oxyl/nitrogen oxide (keto-ABNO/NOx) and oxygen in acetic acid (AcOH), affording the corresponding fluoroalkyl ketones in high yield. This operationally simple reaction can be performed under mild conditions, and was applied to a wide range of alcohols (20 examples), thus demonstrating a high functional group tolerance. Moreover, a modified one-pot protocol based on this method was able to convert an aldehyde to a trifluoromethyl ketone on a gram scale.

Organocatalytic Aerobic Oxidation of α‐Fluoroalkyl Alcohols to Fluoroalkyl Ketones at Room Temperature

AbstractThe organocatalytic aerobic oxidation of electron‐deficient α‐fluoroalkyl alcohols at room temperature is described. The resulting fluoroalkyl ketones are versatile synthetic intermediates for a variety of fluorine‐containing molecules. This otherwise difficult transformation has now been accomplished by the reaction of α‐fluoroalkyl alcohols with N‐oxyl radicals, catalytically generated from 9‐azabicyclo[3.3.1]nonan‐3‐one N‐oxyl/nitrogen oxide (keto‐ABNO/NOx) and oxygen in acetic acid (AcOH), affording the corresponding fluoroalkyl ketones in high yield. This operationally simple reaction can be performed under mild conditions, and was applied to a wide range of alcohols (20 examples), thus demonstrating a high functional group tolerance. Moreover, a modified one‐pot protocol based on this method was able to convert an aldehyde to a trifluoromethyl ketone on a gram scale.magnified image

One-step catalytic cyclohexane oxidation to adipic acid using molecular oxygen

Using combination of Mn-Co transition metal species with N-hydroxyphthalimide as a catalyst for one-step oxidation of cyclohexane with molecular oxygen in acetic acid at 353 K can give more than 95% selectivity towards oxygenated products with adipic acid as a major product at a high conversion (ca. 78%). A turnover number of 74 for this partial oxidation are also recorded.

Potential Energy Surfaces for Proton Abstractions from Acetic Acid

The abstractions of hydrogen from both carbon and oxygen in acetic acid by hydride, fluoride, and hydroxide anions have been studied using ab initio electronic structure calculations. Molecular structures were optimized at the Hartree-Fock level of theory using the 6-31++G(d,p) basis set. For energetics, the 6-311++G(d,p) basis set was used, with second- and fourth-order perturbation theory corrections, for both minima and transition states. For the hydride and fluoride ion abstractions of hydrogen from carbon, a small activation energy exists at the Hartree-Fock level, but vanishes when correlation energy corrections are introduced. No other barriers are found for the abstraction reactions, but intermediate minima are found on the F{sup -} + CH{sub 3}COOH {yields} FH + {sup -}CH{sub 2}COOH surface and on the analogous OH{sup -} + CH{sub 3}COOH surface. The calculated heats of formation for both acetic acid anions are in good agreement with the experimental value. The fourth-order perturbation theory calculation of the activation energy for the isomerization of acetate to enolate ion is 50.4 kcal/mol. The G2 values for the gas phase acidities of acetic acid at the OH and CH ends of the molecule are 339.3 and 365.8 kcal/mol, respectively. The former result is in good agreementmore » with the experiment. 26 refs., 5 figs., 5 tabs.« less

ChemInform Abstract: Oxygenation of Alkenylsilanes in the Presence of Thiophenol. Direct and Regiospecific Conversion to α‐Phenylthio Carbonyl Compounds.

AbstractThe substituted vinylsilanes (I) react with thiophenol (II) and oxygen in acetic acid to give the phenylthio ketones (III).

Catalytic reactions involving palladium(II) salts supported on amberlyst

Palladium(II) salts supported on Amberlyst-A21 have been characterised by elemental analyses, infrared and electronic spectra, thermal analysis and Mössbauer measurements. The catalytic properties of these materials have been studied for ester interchange involving vinylacetate and vinyl propionate and the reaction of ethylene and oxygen in acetic acid; the results are compared with a previous study.

ChemInform Abstract: OXIDATION OF O‐XYLENE BY ATMOSPHERIC OXYGEN IN ACETIC ACID

Chemischer InformationsdienstVolume 7, Issue 9 Preparative Organic Chemistry ChemInform Abstract: OXIDATION OF O-XYLENE BY ATMOSPHERIC OXYGEN IN ACETIC ACID S. A. PUGACHEVA, S. A. PUGACHEVASearch for more papers by this authorV. N. ALEKSANDROV, V. N. ALEKSANDROVSearch for more papers by this authorG. S. GOLUBEV, G. S. GOLUBEVSearch for more papers by this author S. A. PUGACHEVA, S. A. PUGACHEVASearch for more papers by this authorV. N. ALEKSANDROV, V. N. ALEKSANDROVSearch for more papers by this authorG. S. GOLUBEV, G. S. GOLUBEVSearch for more papers by this author First published: March 2, 1976 https://doi.org/10.1002/chin.197609091AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume7, Issue9March 2, 1976 RelatedInformation

Liquid-phase oxidation of p-toluic aldehyde by molecular oxygen in acetic acid

1. 1. It was established that in non-catalytic oxidation of p-toluic aldehyde at a temperature of 120–200° the reaction is self-inhibited with a degree of aldehyde conversion of 80–85%. It was assumed that p-cresol formed during the thermal conversion of pertoluic acid is the inhibitor. 2. 2. It was shown that during oxidation of p-toluic aldehyde in the presence of a bromine compound the reaction is non-catalytic. 3. 3. At certain critical concentrations catalysts of liquid-phase oxidation of hydrocarbons function as effective inhibitors in the case of p-toluic aldehyde.

The Influence of Metal Acetates on the Oxidation of Sorbic Acid by Molecular Oxygen in Acetic Acid and Comparison of the Results with Those for Eleostearic Acids.

The Influence of Metal Acetates on the Oxidation of Sorbic Acid by Molecular Oxygen in Acetic Acid and Comparison of the Results with Those for Eleostearic Acids.