ジメチル安息香酸およびプソイドキュメンのアルカリ性過マンガン酸力リウ厶酸化

抄録

Potassium permanganate oxidation of alkyl benzoic acids and pseudocumene has been carried out in an aqueous alkaline solution. 2, 4-and 2, 5-Dimethylbenzoic acids gave 2-methylterephthalic acid and 4-methylisophthalic acid, respectively, as an intermediate in the preparation of trimellitic acid. In the oxidation of 3, 4- dimethylbenzoic acid and competitive oxidation of isomeric toluic acids, the relative reactivity of the methyl groups has been established, as follows : para>reta>ortho. By partial oxidation of mesitoic acid, 2, 6-dimethylterephthalic acid was obtained as main product. In the case of pseudocumene, 2, 4-and 3, 4-dimethylbenzoic, 2-metylterephthalic, and 4-methylisophthalic acids were produced as intermediate products. Their formations were explained by the difference in relative reactivities of the methyl groups.