N,N'-diacetic acid-N'-cyanomethyl, salts thereof, and their preparation

Abstract

A novel intermediate useful in the synthesis of ethylenediaminetriacetic acid (ED3A) or its salts. A salt of N,N'-ethylenediaminediacetic acid (ED2AH.sub.2) is condensed with formaldehyde to form a stable 5-membered ring intermediate. The addition of cyanide across this cyclic material forms ethylenediamine N,N'-diacetic acid-N'-cyanomethyl or salts thereof (mononitrile-diacid), which is useful intermediate in the production of ED3A. The nitrile in aqueous solutions may be spontaneously cyclized to form 2-oxo-1,4-piperazindeiacetic acid (3KP) or salts thereof. In the presence of excess base, salts of ED3A are formed in excellent yield and purity.

Dependencies are inferred from the claim text.