Synthesis of 2,4,5‐triaryl‐5H‐chromeno[4,3‐b]pyridines under microwave radiation

2,4,5-Triaryl-5H-chromeno[4,3-b]pyridines were synthesized from a three-component cascade reaction of 2′-hydroxyacetophenone, aromatic aldehyde, and ammonium acetate catalyzed by 2-1′-methylimidazolium-3-yl-1-ethyl sulfate under microwave irradiation. Nine new bonds and two new rings were formed in one-pot. J. Heterocyclic Chem., (2009).