Process for the preparation of halophthalic anhydrides

摘要

A process for the preparation of a halophthalic anhydride, such as chlorophthalic anhydride, comprising the liquid phase reaction of bromine with a halogen substituted hexa- or tetra-hydrophthalic anhydride to produce halophthalic anhydride and gaseous HBr, and reacting the gaseous HBr with chlorine to regenerate bromine.