The synthesis of novel di- and tricarboxylic acids is described. Starting from diethanolamine, a series of N-substituted diethanol derivatives were prepared which were converted in the subsequent reaction step into the corresponding carboxylic acids by treatment with chloroacetic acid. N,N-bis[2- (carboxymethoxy)ethyl]glycine was obtained by N-alkylation of glycine ethylester with ethyl 2-(2- bromoethoxy)acetate