INVESTIGATION OF THE INDUSTRIALLY APPLICABLE SYNTHESIS OF IMINODIACETIC ACID

Abstract

The present paper deals with the synthesis of iminodiacetic acid, which is the basic material of the production of the plant-protecting agent N-phosphonomethyl glycine. The most economical procedure for the industrial preparation of iminodiacetic acid involves aminolysis of monochloroacetic acid, where the starting materials are monochloroacetic acid, ammonia and Ca(OH)2. We improved the conversion of monochloroacetic acid into the target compound to 91% from the present 67% yield. Our results show that the rate-determining step is the formation of iminodiacetic acid, while a considerable amount of glycine is present. Our important recognition is that glycine, produced together with the desired iminodiacetic acid, can be converted with monochloroacetic acid to iminodiacetic acid after removal of the excess of ammonia from the reaction mixture.