Microwave‐Assisted Iron(III)Chloride Catalyzed One‐Pot Michael Addition‐Cyclization for the Synthesis of 6 <i>H</i> ‐Chromeno[4’,3’:4,5] imidazo[1,2‐a]pyridine

Abstract

Abstract An efficient one‐pot Michael addition‐cyclization reaction has been developed for the synthesis of 6 H ‐chromeno[4’,3’ : 4,5]imidazo[1,2‐a]pyridine under microwave irradiation method. The current protocol paves the way for the synthesis of twenty number of structurally diversified imidazo[1,2‐ a ]pyridines in high yield by the reaction of substituted 2‐aryl‐3‐nitro‐2 H ‐chromenes with 2‐aminopyridines using anhydrous iron(III)chloride. This current protocol is the first report of the preparation of this medicinally significant highly substituted 6 H ‐chromeno[4’,3’ : 4,5]imidazo[1,2‐a]pyridine derivatives under microwave irradiation in good to high yields. The tolerance of a wide range of functional groups, operational simplicity and short reaction times are the significant advantages of this protocol.