A METHOD FOR THE HIGH-EFFICIENCY OF WATER-SOLUBLE CARBODIIMIDE-MEDIATED AMIDATION

Water-soluble carbodiimides are widely used for carboxyl-amine conjuga tion. However, extremely variable and low yields, obtained under a var iety of conditions, have been a serious problem in the coupling. A sim ple method, optimizing various parameters of the coupling reaction, in which N-hydroxysuccinimide is included to assist the 1-ethyl-3-(3-dim ethylaminopropyl)carbodiimide hydrochloride-catalyzed amidation reacti on is described. A product yield of up to 90% is routinely achieved. ( C) 1994 Academic Press, Inc.