Process for preparing 2,5-diphenylterephthalic acid by oxidation

摘要

Provided is a process for preparing 2,5-diphenylterephthalic acid, which is useful in preparing certain polyesters, especially liquid-crystalline polyesters. In this process, p-xylene is di-alkylated with cyclohexene to provide 2,5-dicyclo-hexyl-p-xylene, which is in turn dehydrogenated to provide 2,5-diphenylxylene. 2,5-Diphenylxylene is then oxidized to provide 2,5-diphenylterephthalic acid by utilization of a cobaltous/manganous/bromide oxidation system.