Oxidation of p-cresol with ozone in acetic anhydride

Preparation of aromatic alcohols and aldehydes by oxidation of p-cresol with ozone in acetic anhydride in the presence of sulfuric acid, manganese acetate, and potassium bromide was studied. The optimal oxidation conditions were determined.     

Kinetics and products of the catalytic oxidation of acetamidotoluenes with ozone in acetic acid

The kinetics of acetamidotoluene oxidation in glacial acetic acid in the presence of cobalt acetate is reported. At 95°C and atmospheric pressure, acetamidotoluenes are oxidized by molecular oxygen very slowly: oxidation is complete in 10–12 h, and the major reaction products are acetamidobenzoic acids (27–36% yield). The introduction of ozone into the reactive gas increases the reaction rate by one order of magnitude. The main role of ozone is to generate the active form of the catalyst.     

Oxidation of 2-acetoxytoluene with ozone in acetic anhydride

Kinetics and mechanism of the reaction of ozone with 2-acetoxytoluene in acetic anhydride in the presence of sulfuric acid were studied. It was shown that the prevailing reaction route under these conditions is ozonolysis (89%), and the selectivity of the oxidation of the substrate by the methyl group is no higher 9%. However, in the presence of manganese(II) sulfate as a catalyst, the selectivity increases to 76%. The major reaction products were 2-acetoxybenzyl acetate (59%) and 2-acetoxybenzylidene diacetate (17%). In the presence of a manganese bromide catalyst, the oxidation depth increases, and the major reaction product is already 2-acetoxybenzylidene (66%), while the yield of 2-acetoxybenzyl acetate is 15%. The mechanism of the redox catalysis is considered, that explains the experimental results.     

Decomposition kinetics of ozone complexes with toluene and its deuterated derivatives

Decomposition rate of O₃ complexes with aromatic hydrocarbons (ArX·O₃) in ArXO₃-ArX-CH₂Cl₂ system (ArX=C₆H₅CH₃, C₆H₅CD₃ and C₆D₅CD₃) is described by the equation:

Catalysis of reaction between ozone and 4-hydroxytoluene in acetic anhydride

Kinetics and products of 4-hydroxytoluene oxidation with ozone-air mixture in the presence of transition metal acetates as catalysts have been studied. Main steps of the catalytic series have been considered, and a mechanism of redox catalysis has been proposed which conforms to the experimental data and enables control over the direction, depth, and selectivity of the oxidation. Only manganese(II) acetate has been found to exhibit high catalytic activity in the presence of catalytic amounts of mineral acids. Manganese(II) acetate largely suppresses electrophilic reaction of ozone with the aromatic ring, so that the main reaction direction is oxidation of the methyl group with formation of 4-acetoxybenzyl acetate as the major product (62.6%) and 4-acetoxybenzylidene diacetate as a minor one (10.2%).     

Kinetics and mechanism of the reactions of ozone with guaiacol,veratrol, and veratrol derivatives

The kinetics of the reactions of ozone with compounds modeling structural lignin fragments, viz., phenol, guaiacol, veratrol, veratric aldehyde, and veratric alcohol, was studied. The reaction rate constants were calculated using the mass transfer model for the chemical reaction based on the film theory. The rate constants of the reactions of ozone with compounds of the veratryl series were calculated by the Hammett equation. The major ozonation products of the studied compounds were determined by HPLC. The ozonation mechanism was proposed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 276–281, February, 2008.     

Kinetics and mechanism of 4-acetoxytoluene oxidation by ozone in an acetic anhydride solution in the presence of manganese bromide catalysts

The kinetics of the reaction of ozone with 4-acetoxytoluene in an acetic anhydride solution in the presence of a manganese bromide catalyst is reported. Under these conditions, the major reaction products are 4-acetoxybenzylidenediacetate (68.0%), 4-acetoxybenzyl acetate (18.5%), and 4-acetoxybenzyl bromide (1.6%). The effect of manganese(II) acetate and potassium bromide on the selectivity of oxidation at the methyl group has been investigated. A probable redox catalysis mechanism explaining the experimental data is considered.     

Catalytic oxidation of toluene by ozone in the acetic acid-sulfuric acid system

Oxidation of toluene by ozone was studied in the system constituted by acetic and sulfuric acids in the presence of manganese(II) acetate and sodium bromide. The effect of sulfuric acid and the catalyst on the yield of benzoic acid and on the oxidation rate was considered. The optimal ozonization conditions were determined. A scheme of redox catalysis that accounts for experimental data was suggested.     

Kinetics of reactions between methyl and acetyl radicals in gas phase produced by flash photolysis of acetic anhydride

The reaction products of photolysis of acetic anhydride in gas phase at 25°C, where He or CO₂ was present as buffer gas, were analyzed by gas chromatography. The extent of photodissociation was 52% ± 5% and the extent of intramolecular hydrogen transfer reaction producing acetic acid and ketene was 48% ± 5%. The rate constants of the hydrogen exchange and radical combination reactions between methyl and acetyl radicals were calculated from the amounts of products. The value of the ratio of the rate constants of hydrogen exchange and radical combination reactions between methyl and acetyl radicals, ??₇/??₆ = 0.15, indicates that acetyl radical is a relatively poor hydrogen donor. The corresponding ratio of rate constants for the reactions between two acetyl radicals, ??₉/??_s = 0.42, indicates that acetyl radical is a better hydrogen acceptor than methyl radical.     

Preparation of 3-substituted isocoumarins in the reactions of homophthalic anhydride and its derivatives

Acetylation of 4-nitrohomophthalic anhydride gave 4-acetyl-7-nitroisochroman-1,3-dione, which was converted to 3-methyl-7-nitroisocoumarin. 3-Benzylisocoumarin derivatives were synthesized by reaction of homophthalic anhydrides with arylacetic acids in acetic anhydride and triethylamine.Communication XXVIII from the series Condensation of Dicarboxylic Acid Anhydrides with Compounds Containing Active Methylene Groups. See [1] for communication XXVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1487–1489, November, 1977.     

Action of acetic anhydride on benzo-1,5-diazepine derivatives

Under the action of acetic anhydride in benzene, 7-amino-2,4-dimethyl- and 2,4-dimethylbenzo-1, 5-diazepine undergo cleavage at the-C=N-bond with simultaneous acylation of the primary amino groups formed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1135–1137, August, 1970.     

Kinetics and mechanisms of the ozone/bromite and ozone/chlorite reactions

Ozone reactions with XO(2)(-) (X = Cl or Br) are studied by stopped-flow spectroscopy under pseudo-first-order conditions with excess XO(2)(-). The O(3)/XO(2)(-) reactions are first-order in [O(3)] and [XO(2)(-)], with rate constants k(1)(Cl) = 8.2(4) x 10(6) M(-1) s(-1) and k(1)(Br) = 8.9(3) x 10(4) M(-1) s(-1) at 25.0 degrees C and mu = 1.0 M. The proposed rate-determining step is an electron transfer from XO(2)(-) to O(3) to form XO(2) and O(3)(-). Subsequent rapid reactions of O(3)(-) with general acids produce O(2) and OH. The OH radical reacts rapidly with XO(2)(-) to form a second XO(2) and OH(-). In the O(3)/ClO(2)(-) reaction, ClO(2) and ClO(3)(-) are the final products due to competition between the OH/ClO(2)(-) reaction to form ClO(2) and the OH/ClO(2) reaction to form ClO(3)(-). Unlike ClO(2), BrO(2) is not a stable product due to its rapid disproportionation to form BrO(2)(-) and BrO(3)(-). However, kinetic spectra show that small but observable concentrations of BrO(2) form within the dead time of the stopped-flow instrument. Bromine dioxide is a transitory intermediate, and its observed rate of decay is equal to half the rate of the O(3)/BrO(2)(-) reaction. Ion chromatographic analysis shows that O(3) and BrO(2)(-) react in a 1/1 ratio to form BrO(3)(-) as the final product. Variation of k(1)(X) values with temperature gives Delta H(++)(Cl) = 29(2) kJ mol(-1), DeltaS(++)(Cl) = -14.6(7) J mol(-1) K(-1), Delta H(++)(Br) = 54.9(8) kJ mol(-1), and Delta S(++)(Br) = 34(3) J mol(-1) K(-1). The positive Delta S(++)(Br) value is attributed to the loss of coordinated H(2)O from BrO(2)(-) upon formation of an [O(3)BrO(2)(-)](++) activated complex.     

Kinetics of amine-cyclic anhydride reactions in moderately polar solutions

The validity of extrapolating the reactivity of low molar mass compounds in solution to the polymer-analogous chemistry between polymer-bound functionality is investigated for the reaction of primary amines with cyclic anhydrides in the moderately polar solvents, anisole and tetraethyleneglycol dimethylether. The kinetics of amic-acid formation and imidization of polymeric and small molecule mixtures measured by Fourier-Transform Infrared Spectroscopy at near-ambient and elevated temperatures are compared. A Significant decrease in both reaction rates is observed upon changing the primary amine from aliphatic to benzylic, benzylic to 1,2-diphenylethylamine, and 1,2-diphenylethylamine to polystyrene-bound 1,2-diphenylethylamine. Reasons for the influence of polymer-bound chemical functionality on the reaction rates for these amines are discussed. The imidization step is found to be rate limiting in the reaction of phthalic anhydride with benzylamine at the functional group concentrations reported (0.14M or less). © 1995 John Wiley & Sons, Inc.     

Multiphase telomerisation of butadiene with acetic acid and acetic anhydride

Two different routes to acetoxyoctadiene are presented. The first one uses the well-known telomerisation of butadiene with acetic acid operating in a multiphase semi-batch mode. The second reaction involves the cleavage of acetic anhydride, hydrogen transfer via ketene formation and thus a telomerisation as well.     

Nitro derivatives of the thiophene series. 4. Nitration of thiophene derivatives with metal nitrates in acetic anhydride

The nitration of 2-formylthiophene, 2-acetothienone, and unsaturated ketones of the thiophene series with copper and aluminum nitrates in acetic anhydride at various temperatures was studied. At low temperatures 2-acetothienone gives a mixture of 4- and 5-nitro isomers, while 2-formylthipphene gives only a 5-nitro-substituted compound in the diacetate form; ,-unsaturated ketones are not nitrated under these conditions. When the reaction is carried out at 70–90 °C, one can obtain mixtures of nitro ketones in the case of unsaturated ketones; 2-formylthiophene is oxidized to thiophene-2-carboxylic acid, while 2-acetothienone gives a substance, the structure of which could not be established. The reaction of copper and aluminum nitrates with acetic anhydride was investigated by means of thermal and x-ray diffraction analysis. It is shown that the reaction is accompanied by the formation of free nitric acid, and the nitrating agent in these mixtures is consequently the nitronium cation.See [1] for communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 913–916, July, 1981.     

Reaction of hexafluoroacetone with acetic anhydride

Conclusions When acetic anhydride reacts with hexafluoroacetone it acts not as an acetylating agent, but as a compound containing an active methylene group.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1661–1662, September, 1966.     

Study of the products of the reaction of succinic anhydride derivatives with urea

Conclusions The product of the reaction of isododecenylsuccinic anhydride with urea at 120–160°C is isododecenylsuccinimide.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1900–1902, August, 1988.