Chemical reactivity of 3-hydrazino-5,6-diphenyl-1,2,4-triazine towards pi-acceptors activated carbonitriles

摘要

Behaviour of 3-hydrazino-5,6-diphenyl-1,2,4-triazine 1 as electron donor towards different electron acceptors activated carbonitriles has been investigated and a novel fused heterocyclic system and 2,3-disubstituted 1,2,4-triazines have been obtained. Compound 1 reacts with 1,2-dicyanobenzene as pi-acceptor in DMF to form benzencarboximidamide 16, while reaction of 1 with alpha-bromomalononitrile 17 in boiling DMF affords compound 18. On the other hand, compound 1 reacts with tetracyanoethane 23 in DMF to yield compound 24. The route of reaction in DMF indicates that charge-transfer cornplexation is the key intermediate to obtain new heterocyclic systems. Structures of the products are established by MS, 1R, UV-Vis, CHN and H-1 NMR spectral data.