Meglumine catalyzed expeditious four-component domino protocol for synthesis of pyrazolopyranopyrimidines in aqueous medium

A facile and highly efficient protocol for the one-pot, four-component reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehydes and barbituric acid has been developed using meglumine as an inexpensive, biodegradable and reusable catalyst. This methodology provides a mild and fast route to structurally diverse tricyclic fused pyrazolopyranopyrimidines in good to excellent yields. Simplicity, room temperature reaction conditions, a green solvent, an easy work-up process, inexpensive price and reusability of the catalyst are the main advantages of this method.