Process for the preparation of acid anhydrides

摘要

The invention relates to a novel process for the preparation of symmetrical acid anhydrides of general formula (* CHEMICAL STRUCTURE *) (I) which process comprises reacting a compound of formula (* CHEMICAL STRUCTURE *) (II) with an acid anhydride of formula (* CHEMICAL STRUCTURE *) (III) with removal by distillation of the compound of formula (* CHEMICAL STRUCTURE *) (IV) R2 and X are as defined in the description, and X is chloro or bromo.