METHOD OF DIETHYLENETRIAMINOPENTAACETIC ACID'S AND ETHYLENEDIAMINOTETRAACETIC ACID'S BICYCLIC ANHYDRIDES PREPARATION

摘要

A method of preparing bicyclic anhydrides of diethylene triaminopentaacetic acid and ethylene diaminotetraacetic acid. The invention concerns a method of preparing bicyclic anhydrides of aminopolycarboxylic acids, namely diethylene triaminopentaacetic acid and ethylene diaminotetraacetic acid. The principle is that acetanhydride acts on the given acids, which have had all metal cations removed, in an environment of a mixture of dioxane and pyridine with the catalytic action of N-dimethyl-4-aminopyridine at 70 degrees C for 8 hours.