Amino Acids and Peptides. VI. Curtius Rearrangement of Acyl Amino Acid and Peptide Azides and Reactivity of the Isocyanates

Abstract

Studies on the rate of Curtius rearrangement of acyl amino acid and peptide azides were carried out by means of IR (infrared) spectrophotometry at 25°. It was found that Z-Gly-N₃ and Z-Pro-N₃ were more stable than the other acyl amino acid azides. The reactivity of isocyanates derived from azides with side chain functional groups of various amino acids or additives was also studied. It was found that isocyanates thus obtained were decomposed in the presence of triethylamine, its hydrochloride or 1-hydroxy-benzotriazole at 25°.