A new enzymatic one-pot procedure for the synthesis of carboxylic amides from carboxylic acids

An efficient enzymatic procedure is described for the one-pot conversion of carboxylic acids to the corresponding amides via in situ formation of the ester and subsequent ammoniolysis. The procedure was optimized for the formation of octanamide from octanoic acid via butyl octanoate. It is best performed with lipase SP525 from Candida antarctica B immobilized on Accurel EP100 as catalyst with two equivalents of n-butanol in t-amyl alcohol as solvent. The resulting octanamide was isolated in 93% yield. The one-pot procedure was also applied to oleic acid, which resulted in the isolation of oleamide in 90% yield.