Liquid-Phase Ethyl Benzene Oxidation Catalysed by Manganese Salts

Abstract

The liquid-phase oxidation of ethyl benzene by O2 catalysed by manganese stearate (MnSt2) in a stirred batch reactor has been studied. The main reaction products are ethyl benzene hydroperoxide, methyl phenyl carbinole, and acetophenone. It was established that the reaction includes four basic macro-stages: an induction period, a period of accelerated ethyl benzene consumption, a period of slowing-down, and an inhibition step. It was shown that the initial rate of the second step is described by the equation r 0 = k[EB]0 . The observed experimental data allowed the supposition that the reaction proceeds by the radical-chain mechanism with participation of hydroperoxide radicals. The overall process is possibly initiated by Mn3+ ions.

Mn(ii) acetate: an efficient and versatile oxidation catalyst for alcohols

“…S4 in the ESI †) which is believed to be formed as a result of catalyst poisoning. 60 These results show importantly how the Mn(II) centres of the precatalyst are likely oxidised through one-electron oxidation. The Mn species present in a soluble form in the reaction mixture containing TFA and tBuOOH were, on the other hand, studied by the Evans' NMR method (see section 2.4 for the details).…”

Development of the Process of p-Nitroacetophenone and Benzoic Acid Manufacture by the Liquid-Phase Oxidation of Aromatic Compounds

“…The addition of p -NEBHP and p -NBA in the amounts comparable to those observed in the reaction did not affect the rate. Thus, all of the effects are analogous to those observed during the “stationary” ethyl benzene oxidation. , The only differences are the absence of both the induction time and of the catalyst poisoning. This is evidently caused by the fast Mn 2+ → Mn 3+ transition.…”

“…The experimental procedure was described earlier . All of the oxidation experiments were run in a stirred batch reactor.…”

Large-Scale Oxidations in the Pharmaceutical Industry

“…Using hydrogen peroxide and a tungsten catalyst, cyclohexanol is oxidized to cyclohexanone, a Baeyer−Villiger oxidation occurs followed by hydrolysis, and the product hydroxyl acid is oxidized further to the diacid ( 306 ). The oxidation of ethylbenzene to benzoic acid using oxygen and a manganese catalyst was reported, and the kinetics of this process were studied carefully. −

71 Baeyer−Villiger Oxidations in Oxidation Cascades

…”