Facile, one-pot, four-component synthesis of a new series of imidazo[1,2-a]pyridines in presence of TPAB in EtOH under reflux conditions

摘要

A convenient, regioselective, novel, and elegant one-pot, four-component reaction was designed for synthesis of a series of new of imidazo[1,2-a]pyridines using aryl glyoxal monohydrates, ethyl acetoacetate, hydrazine hydrate, and 2-aminopyridine in presence of tetrapropylammonium bromide under reflux in EtOH as solvent. The main advantages of this protocol include the availability and low cost of the starting materials, short reaction time, convenient operation, easy workup process, highly facile operation, nonhazardous byproducts, and high yield (82-94%).