Patent ID: 8309759

Claim:
A process for preparing an ether carboxylate of formula (I): comprising reacting a corresponding alkoxylate of formula (II): wherein R1 is independently a C 1 - to C 50 -alkyl, mono-, di-, tri-, or higher polyamine, X is independently O, COO, CH 2 —NH—O for q=1 and r=0 or N, N(CH 2 ) t O for q=2 and r=0 to 50, r is independently an integer from 0 to 50, R2 is independently H or C 1 - to C 10 -alkyl, R3 is independently H or C 1 - to C 10 -alkyl, R4 is independently H or C 1 - to C 10 -alkyl, M is independently H or a metal, n is independently from 0 to 50, m is independently from 0 to 40, p is independently from 0 to 40, q is independently from 1 to 20, s is independently 0 or 1, t is independently from 0 to 20, provided that n+m+p is at least 1, and R is independently C 1 - to C 50 -alkyl, C 1 - to C 50 -alkenyl, C 1 - to C 50 -alkynyl, C 6 - to C 50 -aryl, C 6 - to C 50 -alkylaryl, H or a metal, with a base in the presence of a transition metal catalyst, such that the base is added to the reaction mixture discontinuously at two or more times or continuously over a period above 30 minutes.