Amide Bond Formation via Reversible, Carboxylic Acid-Promoted Lactone Aminolysis

Organic Process Research & Development 4(5) 1177-1181, DOI: 10.1021/op1001269

a rapid carboxylic acid-promoted lactone aminolysis is reported. Anumber of carboxylic acids were found to promote this amide bond-forming transformation, with aliphatic acids being the most efficient. This reaction is an equilibrium process (Keq ≈ 1.8), and mechanistic investigations are consistent with mediation of a kinetically important proton-transfer step by the carboxylate, i.e., the conjugate base of the acid employed."