Abstract

The use of multicomponent reactions as potential synthetic processes, ionic liquids as catalysts and water as reaction medium is a suitable approach that respects, in some extent, the requirements of sustainable chemistry. In this context, we report, herein, an efficient and high yielding four-component synthesis of 6-amino-4-aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles involving ethyl acetoacetate, hydrazine hydrate, malononitrile, and various aromatic aldehydes using octyltriphenylphosphonium bromide as an effective and recoverable catalyst and water as solvent under mild reaction conditions.

Keywords: Aqueous medium, ionic liquid, multicomponent reactions, octyltriphenylphosphonium bromide, pyranopyrazoles, rate enhancement, triphenylphosphine.