To a solution mixture of tert-butyl 4-(2-nitrophenyl)-2-(5-phenylpyridine-3-carboxamido)benzoate (0.28 g) in chloroform (3.0 mL) and methanol (2.0 mL), 10% palladium-carbon (0.13 g) was added, followed by stirring under a hydrogen atmosphere at room temperature for 5 hours and 40 minutes. The insoluble substance was removed by filtration, and the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography [eluent: 100-90% chloroform/methanol] to obtain 0.22 g of tert-butyl 4-(2-aminophenyl)-2-(5-phenylpyridine-3-carboxamido)benzoate as a light yellow solid.
