Preparation of Diglycolamides via Schotten–Baumann Approach and Direct Amidation of Esters

Diglycolyl chlorides, commercially available or obtained from the corresponding dicarboxylic acids, have been converted into the corresponding diamides by reaction with a wide range of amines in an organic-aqueous biphasic system (Schotten–Baumann approach) in high yields. Treatment with poly(4-styrenesulfonic acid) afforded the pure compounds. Substituted diglycolyl diesters, obtained by coupling of commercial monoesters, were transformed directly in the corresponding diamides in the presence of aluminum trichloride as catalyst in good yields.