Microwave-Assisted, One-Pot Reaction of Pyridines, α-Bromoketones and Ammonium Acetate: An Efficient and Simple Synthesis of Imidazo[1,2-a]-pyridines

A novel and efficient synthesis of imidazo[1,2-a]pyridines is described. N-Phenacylpyridinium bromides, which were prepared in situ from the addition of pyridines to alpha-bromoketones, undergo nucleophilic addition of ammonium acetate under microwave irradiation and solvent-free conditions to afford the corresponding imidazo[1,2-a]pyridines in excellent yields.