Autoxidation of bis(ortho dialkyl-phenoxy)benzophenones

摘要

A method is described for autoxidizing a novel class of bis(ortho dialkyl-phenoxy)benzophenones directly to their corresponding dianhydrides. The method comprises autoxidizing the benzophenones in a solution of an aliphatic monocarboxylic acid having 3 to 8 carbon atoms with oxygen in the presence of a heavy metal oxidation catalyst and a promoter at a temperature of at least about 120 DEG C. to form the dianhydride. The dianhydrides are used in the preparation of organic high temperature polymers such as polyetherimides.