Patent ID: 6867327

Claim:
A process for the preparation of 1,2-diaminocyclohexanetetraacetic acid comprising the steps of: (a) neutralizing chloroacetic acid in an aqueous medium with a non-metal amino or hydroxy base compound at a temperature less than 10° C.; (b) reacting said neutralized chloroacetic acid with 1,2-diaminohexane at temperatures less than 80° C.; (c) adding a non-metal amino or hydroxy base to complete neutralization so as to form an aqueous mixture; (d) heating the aqueous mixture at less than 100° C.; (e) filtering the mixture from (d); (f) treating the aqueous filtrate with hydrochloric acid until a precipitate forms; (g) filtering the aqueous filtrate; and then (h) recovering 1,2-diaminocyclohexanetetraacetic acid and optionally redissolving said 1,2-diaminocyclohexanetetraacetic acid in an aqueous solution and repeating steps (c) to (g).