Abstract. The kinetic regularities and mechanisms of oxidation reactions of 4-aminotoluene and its acylation derivatives by the gases that contain ozone in the glacial acetic acid have been studied. The process of liquid-phase catalytic oxidation of 4-acetaminotoluene by ozone in the presence of transition metal salts and their mixtures with potassium bromide to the corresponding acetaminobenzoic acid has been investigated.
Проведені дослідження кінетичних закономір-ностей і механізму реакцій окиснення 2-і 3-аміно-толуену та їх ацильованих похідних у крижаній оцтовій кислоті. Вивчено процес каталітичного рідкофазного окиснення 2-і 3-ацетамідотолуену озоном у присутності солей перехідних металів та їх сумішей з калій бромідом до відповідних аце-тамідобензойних кислот Ключові слова: 2-амінотолуен, 3-амінотолуен, 2-ацетамідотолуен, 3-ацетамідотолуен, озон, окиснення, 2-ацетамідобензойна кислота, 3-аце-тамідобензойна кислота Проведены исследования кинетических зако-номерностей и механизма реакций окисления 2-и 3-аминотолуола и их ацилированных произ-водных в ледяной уксусной кислоте. Изучен про-цесс каталитического жидкофазного окисления 2-и 3-ацетамидотолуола озоном в присутствии солей переходных металлов и их смесей с броми-дом калия до соответствующих ацетамидобен-зойных кислот Ключевые слова: 2-аминотолуол, 3-аминото-луол, 2-ацетамидотолуол, 3-ацетамидотолуол, озон, окисление, 2-ацетамидобензойная кислота, 3-ацетамидобензойная кислота
The kinetics and mechanism of oxidation of 4-bromoacetophenone by ozone in acetic acid solution have been studied. It was shown that 77% of the starting material is oxidized by the benzene ring; 8% of 4-bromobenzoic acid and small amounts of carbon (IV) oxide were identified among the side chain ozonation products. The main reaction products are aliphatic peroxide compounds, which have in their structure one hydroperoxide group. Manganese (II) acetate was shown to be the most effective catalyst for the side chain reaction of 4-bromoacetophenone in acetic acid. High selectivity for the side chain is achieved only at sufficiently high concentrations of catalyst ([Mn(OAc)2]0:[ArH]0=1:4). The main product of the catalytic oxidation of 4-bromoacetophenone is 4-bromobenzoic acid with a yield of 82.5%. The found dependences of the rate of oxidation of 4-bromoacetophenone by ozone on the concentration of reactants are described by the kinetic equation of the third order, the reaction rate has the first order with respect to each reagent. It was found that the decisive role in the selective oxidation of 4-bromoacetophenone is played by two-stage oxidation, in which ozone predominantly reacts with the reduced form of manganese, and the introduction of the substrate into side chain oxidation is carried out by the reaction with the oxidized form of metal. According to the research results, the mechanism of catalytic ozonation of 4-bromoacetophenone in acetic acid has been proposed, which involves ion-radical non-chain oxidation of the substrate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.