An Expeditious One-pot Synthesis of Imidazo[1,2-a]pyridines using ZnCl2.SiO2 as a Recyclable Heterogeneous Catalyst under Solvent-free Condition

Abstract

Synthesis of imidazo[1,2-a]pyridines over several solid supported catalysts has been investigated. Among these catalysts, ZnCl2 .SiO2 (silzic) showed excellent yields and short reaction times. The silzic catalyst could be recovered and reused in five reaction cycles. The present procedure offers several advantages such as short reaction time, simplicity of the reaction procedure, the elimination of solvents, simple workup, recovery and reusability of the catalyst.