An Efficient Organocatalyst for Environmentally benign Synthesis of Pyranopyrazole Derivatives in Aqueous Medium

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.