Crystals of alanine N-acetic acid precursors, process to prepare them and their use

摘要

The present invention relates to alanine N-acetic acid precursors of formula (i) COOM-CH(CH3)—NH—(CH2CN), wherein M is hydrogen (alanine N-monoacetonitrile), or (ii) COOM-CH(CH3)—N—(CH2CN)2, wherein 0 to 50% of all M is sodium or potassium and 50 to 100% of all M is hydrogen (alanine N,N-diacetonitrile and its partial sodium or potassium salts) comprising L-alanine to D-alanine in a range of from 75:25 to 50:50 (L:D), or (iii) COOM-CH(CH3)—N—(CH2CONH2)2, wherein M is hydrogen (alanine N,N-diacetamide), in the form of crystals, and relates to a process to prepare these precursors and their use, especially to give MGMA or MGDA.