Binary heterocyclic systems containing the ethylideneamino linkage: synthesis of some new heterocyclic compounds bearing the naphtho-[2,1-b]furan moiety

Ethylidene hydrazine (4a,b) and thiazolidin-4-one (5) derivatives were synthesized by the reaction of ethylidenethiosemicarbazide derivative (3a) with α-haloketone/ethyl bromoacetate, respectively. Hetrocyclization of ethylideneacetohydrazide derivative (7) with o-phenolic aldehydes gave the corresponding coumarin derivatives (8,9). The interaction of 7 with acetylacetone afforded the corresponding pyridine derivative (10). Treatment of the arylidene derivative 11b with malononitrile afforded the corresponding pyran derivative (12). The new products 3-12 were subjected to IR, 1H NMR and mass spectra studies.