One-pot synthesis of imidazo[1,2-alpha]pyridine thioethers using imidazo[1,2-alpha]pyridines, arylsulfonyl chlorides and hydrazine

A one-pot reaction of making RS-substituted imidazo[1,2-alpha]pyridine derivatives by directly using aryl or alkylsulfonyl chloride and hydrazine was developed, selectively giving good yields of the expected products. Compared with previously reported methods of using ArSO2NHNH2 as a sulfur source, this method is much cheaper, more practical and convenient and enriches current methods to make thioether-containing compounds, providing a good example of green chemistry.