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.
本发明涉及一种制备N,N'-二(2-羟基苯甲基)
乙二胺-N,N'-二
乙酸及其盐的方法,包括在pH值在3至7之间、温度低于60°C的条件下,通过
甲醛、
乙二胺二
乙酸或其盐以及
酚之间的反应制备,其中反应混合物中含有0.2至1.1摩尔当量的碱
金属离子与E
DDA的摩尔量。