Enzymatic synthesis of glycamide surfactants by amidification reaction

The condensation of a secondary amine (N-methyl-glucamine) with oleic acid was selected as a reaction model to study the production of glycamide surfactants by enzymatic amidification. Reactions catalyzed by immobilized lipase from Candida antarctica were carried out in 2-methyl-2-butanol. The acido-basic conditions (through the N-methyl-glucamine/oleic acid ratio) control the chemoselectivity of the reaction allowing the synthesis of either amide, ester or amide-ester. At 90 degrees C and with a N-methyl-glucamine/acid ratio of 1, a 100% conversion yield with 97% of amide synthesis was obtained in less than 50 hours. The process was applied to the preparation of a range of amides using various amines and acyl donors. This process is the first that describes successful amide bond synthesis from a hydroxylated secondary amine and fatty acid or fatty acid ester. (C) 1997 Elsevier Science Ltd.