An Efficient Three-Component Tandem Approach for the Synthesis of Imidazoheterocycle-Hydrazine Derivatives under Mild Conditions

An three-component tandem reaction for the synthesis of imidazo[1,2-a]pyridine-hydrazines was accomplished with the easily available fonnvl methyl bromides, pvridin-2-amines and azodifonnates. This tandem reaction process includes the generation of imidazo[1,2-a]pyridines followed by C(3)-H hydrazination in a sequential way, instead of the classical step-by-step methods. The approach features simple operation, mild conditions (transition-metal-free and low reaction temperature) as well as good tolerance of substrates. Note that fonnvl methyl bromides and pyridin-2-amines bearing electron-donating groups are benefit for this reaction, affording target products in excellent yields.