Oxidation of di- and trimethyl aromatic hydrocarbons having ortho-oriented methyl groups in liquid phthalic acid

摘要

Catalytic liquid phase molecular oxygen oxidation of methyl-substituted aromatic hydrocarbons having two or more methyl-substituents on adjacent ring carbon atoms in acetic acid reaction medium have, in general, resulted in a substantial production of the desired ortho-oriented di-, tri-, and higher polycarboxylic substituted aromatic acids but also in the co-production of substantial amounts of oxygenated intermediates including methyl-substituted mono- and non-ortho polycarboxylic acids. Several theories have been proposed, including inherent auto-inhibiton, for such incomplete oxidations.