A novel one-pot three-component reaction: Synthesis of triheterocyclic 4 H-pyrimido[2,1- b]benzazoles ring systems

Abstract

A novel one-pot three-component condensation reaction of an aldehyde, β-ketoester and 2-aminobenzimidazole or 2-aminobenzothiazole in 1,1,3,3- N, N, N′, N′-tetramethylguanidinium trifluoroacetate as an ionic liquid is described. During the course of this reaction 4 H-pyrimido[2,1- b]benzimidazoles or 4 H-pyrimido[2,1- b]benzothiazoles are formed in high yields at 100 °C. The ionic liquid can be recovered conveniently and reused efficiently.