One-pot synthesis of new functionalized 4H-chromen-4-ylidene derivatives

A simple synthesis of new series of functionalized chromene derivatives through an efficient, one-pot, multicomponent reaction of nitroketene N,S-acetals, salicylaldehydes, and cyanoacetohydrazide in ethanol at ambient temperature in good to high yields is reported. This novel efficient method has the advantages of mild reaction conditions, absence of catalyst, simple work-up, and the non-chromatographic purification of products.