One Pot Multicomponent Synthesis of Pyranopyrazoles using Tetra Butyl Ammonium Bromide as Catalyst in Aqueous Media

A four-component one-pot method to synthesize pyranopyrazoles from aromatic aldehydes, malononitrile, ethylacetoacetate and hydrazinehydrate using tetrabutyl ammonium bromide as a catalyst (20 mol %) in aqueous media is described herein. This method is simple and provides several advantages such as, good yields, short reaction time, environmentally friendly and mild reaction conditions. Use of environmentally benign water as a solvent is also a major advantage of using this method. Keywords-Aromatic Aldehydes; Malononitrile; Ethylacetoacetate; Pyranopyrazoles; TBAB.