Citric Acid → N-[6-(4-aminophenoxy)imidazo[1,2-a]pyridin-2-yl]cyclopropanecarboxamide

Participants

Reaction Conditions

Reaction Steps

To a solution of benzyl [4-({2[(cyclopropylcarbonyl)amino]imidazo[1,2-a]pyridin-6-yl}oxy)phenyl]carbamate (500 mg, 1.13 mmol) in 1,2-dimethoxyethane (15 mL) was added 0.15 mol/L aqueous barium hydroxide solution (10 mL), and the mixture was stirred at 90° C. for 36 hr. After cooling to room temperature, the reaction mixture was adjusted to pH about 5 with citric acid, and to pH about 10 with saturated aqueous sodium hydrogen carbonate. The mixture was extracted with ethyl acetate/tetrahydrofuran, and the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and filtered. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate=50/50→0/100) to give the title compound (223 g, 64%).

Provenance & Evidence