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

Abstract

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 π–acceptor in DMF to form benzencarboximidamide 16, while reaction of 1 with ⍺-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 complexation is the key intermediate to obtain new heterocyclic systems. Structures of the products are established by MS, IR, UV-Vis, CHN and ¹H NMR spectral data.