Creatinine, lactam and cyclic peptide formation by the action of C2N2 on creatine, omega-amino acids and peptides.

Cyanogen, C2N2, affords a means to drive intramolecular conversion of ammonium salts to amides. Unlike other carboxyl activating agents, such as carbodiimides, used in peptide syntheses expressly to drive intermolecular condensations to form amide (peptide) bonds, C2N2 appears restricted to driving only intramolecular condensations. Rates decreased as a function of solvent composition as follows: organic much greater than 70%-80% aqueous organic much greater than 50% aqueous organic greater than H2O.