Revisiting the reaction between diaminomaleonitrile and aromatic aldehydes: a green chemistry approach.

The reaction between diaminomaleonitrile (DAMN) and aldehydes and the resulting monoimines are well known. Since the standard reaction conditions involve the use of toxic solvents (typically methanol), we have sought to apply green chemistry principles to this reaction by either using water as the solvent without any catalysts or employing "solvent-free" conditions. The monoimines derived from DAMN are of interest as precursors for obtaining different heterocyclic systems and linear polymers. The methodologies used have significant advantages with regards to cost and environmental considerations.