Process for the preparation of glycine-N,N-diacetic acid derivatives from the reaction of glycine derivatives or their precursors with formaldehyde and an alkalimetal cyanide in an acidic aqueous medium

摘要

Prepn. of glycine-N,N-diacetic acid derivs. of formula (I), where R = 1-30C alkyl or 2-30C alkenyl, which can also contain, as substits., up to 5 hydroxyl gps., formyl gps., 1-4C alkoxy gps., phenoxy gps. of 1-4C alkoxycarbonyl gps., and which can be interrupted by up to 5 non-adjacent O atoms, alkoxylate groupings of formula -(CH2)k-O-(A1O)m-(A2O)n-Y, phenyl alkyl gps. with 1-20C atoms in the alkyl, phenyl, a 5- or 6-membered (un)satd. heterocyclic ring with up to 3 heteroatoms from N, O and S which can also be benzo-condensed, whereby all phenyl cores and heterocyclic rings given for R can also contain as substits. up to 3 1-4C alkyl gps., hydroxyl, gps., carboxyl gps., sulpho gps. or 1-4C alkoxy carbonyl gps., or a gp. of formula (II); A = 1-12C alkylene bridge or a chemical bond; A1, A2 = 2-4C 1,2-alkylene gps.; Y = H, 1-12 C alkyl, phenyl or 1-4 C alkoxycarbonyl; k = 1, 2 or 3; m, n = 0-50; m+n = at least 4; and M = H, alkali metal, alkaline earth metal, ammonium or substd. ammonium in the corresp. stoichiometric quantities, comprises reacting corresp. 2-substd. glycines or 2-substd. glycine nitriles or double glycines of formula (III) or double glycine nitriles of formula (IV) or precursors of the glycine derivs. given as starting materials with formaldehyde and alkali metal cyanide in aq. alkaline medium at a pH of 8-14. The novelty is that 0.5-30 % of the quantity of alkali metal cyanide required for reaction is added to the glycine derivs. or their precursors and then the remaining amt. of alkali metal cyanide and the formaldehyde is added simultaneously over 0.5-12 hrs.