Oxidation of Toluic Acids in Molten Potassium Hydroxide with Manganese Dioxide

Studies on the Oxidation of Toluic Acids in Molten Potassium Hydroxide. I

Abstract

A new oxidation system of toluic acids which is performed in molten potassium hydroxide (1) with manganese dioxide (2) has been studied. Terephthalic acid was obtained in 87mol% yield from p-toluic acid (3), under the condition of molar ratio (2) / (3) 3.0, weight ratio (1) / (3) 8, reaction temperature 275 °C and reaction time 1 hr. Isophthalic acid was obtained in 57 mol % yield from m-toluic acid (4) under the condition of molar ratio (2) / (4) 3.0, weight ratio (1) / (4) 8, reaction temperature 200°C and reaction time 2 hr. Phthalic acid was obtained in 52 mol % yield from o-toluic acid (5) under the condition of molar ratio (2) / (5) 3.0, weight ratio (1) / (5) 8, reaction temperature 250°C and reaction time 1 hr.