Ga(OTf)3-promoted synthesis of functionalized 2-carbonyl-imidazo[1,2-a]pyridines derived from ethyl α-benzotriazolyl-α-morpholinoacetate

Abstract

An efficient route to the synthesis of 3-amino-2-ethoxycarbonyl imidazo[1,2-a]pyridine derivatives starting from ethyl α-benzotriazolyl-α-morpholinoacetate has been developed. By the reactions between primary heterocyclic amidines and isocyanides catalyzed by Ga(OTf)₃, target compounds were obtained in moderate to good yields. This in turn will set the stage for the wide application of this useful reaction for the synthesis of 3-amino-2-carbonylimidazo[1,2-a]pyridines based on imidazo[1,2-a]pyridine privileged structures.