Process for the preparation of aromatic dicarboxylic acid dichlorides

摘要

A single-stage process for the preparation of high purity aromatic dicarboxylic acid dichlorides by reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid mixture with phosgene in the presence of betaines as catalysts and optionally in a solvent or diluent, and the application of the aromatic dicarboxylic acid dichlorides for making polycondensates.