Microwave-Assisted Iron(III)Chloride Catalyzed One-Pot Michael Addition-Cyclization for the Synthesis of 6H-Chromeno4',3':4,5 imidazo1,2-apyridine

摘要

An efficient one-pot Michael addition-cyclization reaction has been developed for the synthesis of 6H-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-2H-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 6H-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.