One-pot Lewis acid assisted synthesis of indole-3-sulfonamide and imidazo[1,2-a]pyridine-3-sulfonamide using Burgess reagent in a microwave reactor

Indole-3-sulfonamides and imidazo[1,2-a]pyridine-3-sulfonamides have served as useful derivatives for development of useful therapeutics and agrochemicals. An efficient one-pot yet two step synthesis of these key derivatives was developed using a modified Burgess reagent and Lewis acids under microwave reaction conditions. A systematic study to optimize the synthetic yield of indole-3-sulfonamide, and subsequent application of the developed reaction condition for the synthesis of imidazo[1,2-a]pyridine derivatives is reported in this paper.