Benzotriazole-assisted synthesis of α-acylaminonitriles and a conceptually novel method for peptide elongation

Abstract
A general method for the synthesis of α-acylamino nitriles is reported. Initially, the adducts resulting from Mannich-type condensation of benzotriazole with an aldehyde and an amide are prepared. These undergo elimination of benzotriazole with cyanide to give α-arylamino nitriles in high yields. Subsequent hydrolysis of the nitrile function to the di-amides, followed by a repetition of the cyanoalkylation sequence, constitutes a novel method for the elongation of peptides.