Process for preparing polybasic carboxylic-acid chlorides, as well as intermediates therefor

Abstract

Abstract 1. Process for the preparation of acid chlorides of polybasic carboxylic acids, characterized in that polymeric anhydrides of polybasic carboxylic acids are first prepared from polybasic carboxylic acids, which contain at least two carboxyl groups which are not capable of forming an inner anhydride, by reaction with anhydrides of monobasic C2 - to C4 -carboxylic acids, a solvent in which the anhydrides of monobasic C2 - to C4 -carboxylic acids are soluble, which has a higher boiling point than these anhydrides and in which the polymeric anhydrides of polybasic carboxylic acids are insoluble being added before or during this reaction, and phosgene is then passed, in the presence of catalysts, into the suspension obtained after the constituents which have a lower boiling point than the solvent have been removed.

Inventors

• 👤 Günter Dr. Stammann
• 👤 Dieter Dr. Freitag
• 👤 Ludwig Dr. Bottenbruch
• 👤 Karlheinz Dr. Feltgen

Bibliographic Details