PROCESS TO PREPARE PHENOLIC ETHYLENEDIAMINE DIACETIC ACID COMPOUNDS

摘要

The present invention relates to a process to prepare N,N'-di(2-hydroxybenzyl) ethylenediamine-N,N'-diacetic acid and salts thereof comprising a reaction between formaldehyde, ethylenediamine diacetic acid or a salt thereof and phenol at a pH of between 3 and 7 and a temperature below 60°Cwherein the reaction mixture contains 0.2 to 1.1 molar equivalents of alkali metalions on the molar amount of EDDA.