Patent ID: 8431734

Claim:
A process for the preparation of N,N′-bis(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid and its derivatives of general formula I: wherein: both R have the same meaning and are selected from H, C 1 -C 4 alkyl, CH 2 OH, SO 3 M, and COOM; and all M have the same meaning and represent hydrogen atom, Na, K or NH 4 ; which comprises: reductive amination of glyoxylic acid with a salan compound of general formula (II) wherein R have the same meaning as defined for formula (I), by hydrogenation with hydrogen in the presence of a hydrogenation catalyst and an amine proton acceptor in a C 1 -C 3 alkanol or their mixtures, a C 1 -C 3 alkanol/water mixture or in water, to obtain the compound of formula (I), wherein M are hydrogen atoms, and if desired, converting it further into compound of formula (I), wherein M represent Na, K or NH 4 by the treatment with a corresponding base.