Activated Nitriles in Heterocyclic Synthesis: Novel Synthesis of Pyridazines, Pyridines, Pyrazoles and Polyfunctionally Substituted Benzene Derivatives

Abstract

Knoevenagel condensation of benzoylacetonitrile with malononitrile afforded the corresponding ylidene derivative which could be converted into pyridazine derivative on coupling with benzenediazonium chloride and cyclization.Similarly benzoylacetonitrile underwent self condensation to yield either the benzene derivative or the ylidene derivative.The latter could be converted into a variety of heterocyclic derivatives on reaction with malononitrile, ethyl cyanoacetate, hydrazine hydrate and benzenediazonium chloride.Polyfunctionally substituted nitriles are highly reactive reagents that have been extensively utilised in heterocyclic synthesis1'*.Recently we have reported that