p-Toluenesulfonic acid catalyzed, isocyanide-free, Groebke–Blackburn–Bienayme (GBB) type multicomponent synthesis of 3-anilino-imdazo[1,2-a]pyridines

Herein, a Groebke–Blackburn–Bienayme (GBB) type multicomponent synthesis of 3-anilinoimidazo[1,2-a]pyridines using commercially available building blocks such as aryl glyoxal, aniline, and 2-aminopyridine has been developed. The key advantage of this method is it avoids the use of foul-smelling isocyanides as one of the key reaction partners in the GBB reaction. The desired products are formed via the three consecutive C–N bond formations in this one-pot reaction demonstrated in the gram scale.