A process for manufacturing 5-hydroxyisophthalic acid.

摘要

In a process for manufacturing 5-hydroxyisophthalic acid by means of oxidizing 5-acyloxy-m-xylene or its oxidation intermediate with molecular oxygen in a solvent consisting of lower aliphatic carboxylic acid and acetic anhydride in the presence of catalyst consisting of heavy metal comprising cobalt as the main component, and a bromine compound, and hydrolyzing the product thereby obtained, an improvement which is characterized in that the oxidation is carried out under pressure of 2-15 kg/cm<2>gauge in the presence of an alkali metal compound amounting to 0.1-1.1 gram atom in terms of alkali metal atom as against 1 gram atom of the heavy metal used for the catalyst. By the present invention there can be obtained high-quality 5-hydroxyisophthalic acid having excellent color from 5-acyloxy-m-xylene.