Liquid-phase catalytic oxidation of methyl derivatives of biphenyl

Author： Koshel’ G. Koshel’ S. Postnova M. Lebedeva N. Kuznetsova E. Belysheva M. Yun’kova T.

ISSN： 0023-1584

Source： Kinetics and Catalysis, Vol.45, Iss.6, 2004-11, pp. : 821-825

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Liquid-phase catalytic oxidation into acids by air was studied for the following hydrocarbons: isomers of cyclohexyltoluenes and cyclohexyl derivatives of para-xylene, mesitylene, pseudocumene, cyclopentyltoluene, cyclohexyladamantane, 4-methylbiphenyl, 2,4-, 2,5- and 3,4-dimethylbiphenyls, hydroxymethylbiphenyls, and hydroxymethylbenzenes. The oxidation of cyclohexyltoluenes involves a methyl group and proceeds without participation of the α-CH bond of the cyclohexyl fragment in the oxidative conversions. The reactivity of the hydrocarbons increases in the order ortho < meta < para. Consecutive conversions of the methyl groups to carboxyls occur during the oxidation of dimethylbiphenyls. In 3,4- and 2,5-dimethylbiphenyls, the methyl groups in the para and ortho positions, respectively, are first oxidized, whereas the reactivity of both of the methyl groups in 2,4-dimethylbiphenyl is virtually the same. The mechanism of the oxidation of hydroxymethylbiphenyls and hydroxymethylbenzenes involves the formation of an unstable cation radical, which is then stabilized by emitting a proton, giving hydroxybenzyl, a more stable radical.