A mixed solution of N-[6-(2-fluoro-4-nitrophenoxy)-3-methylimidazo[1,2-a]pyridin-2-yl]cyclopropanecarboxamide (80 mg, 0.216 mmol), reduced iron (64 mg, 1.08 mmol) and ammonium chloride (116 mg, 2.16 mmol) in ethanol (2 mL)/water (0.5 mL) was stirred at 80° C. for 3 hr. The reaction mixture was diluted with ethyl acetate and filtered through celite. Water was added to the filtrate, and the mixture was extracted 3 times with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and filtered. The solvent was evaporated under reduced pressure to give the title compound (60 mg, 82%) as a slightly yellow solid.
