Ultrasound-Assisted Efficient Synthesis of Azomethine Derivatives of 1-Phenylimidazo[1,5-a]Pyridine

Abstract

In the present research work, ultrasound-assisted synthesis of a series of novel azomethine derivatives of 1-phenylimidazo[1,5-a]pyridine has been achieved. The synthetic route involves the conversion of ethyl-1-phenylimidazo-[1,5-a]pyridine-3-carboxylate to 1-phenylimidazo[1,5-a]pyridine-3-carbohydrazide followed by nucleophilic addition-elimination reaction with diverse aromatic aldehydes. The developed clean and simple protocol offers a set of advantages such as mild reaction conditions, environment friendliness, and high atom economy apart from excellent yields (70–92%). All compounds were found to be stable in atmospheric conditions for a long period of time and were soluble in polar solvents.