To a solution of 5-bromopyridine-3-carboxylic acid (375 mg, 1.87 mmol) in tetrahydrofuran (6 mL) were added oxalyl chloride (204 μL, 2.34 mmol) and N,N-dimethylformamide (20 μL), and the mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated under reduced pressure. The obtained residue and N-{3-[(2-amino[1,2,4]triazolo[1,5-a]pyridin-6-yl)oxy]-4-methylphenyl}-3-(1-cyano-1-methylethyl)benzamide (400 mg, 0.937 mmol) were dissolved in pyridine (7 mL), and the mixture was stirred at room temperature for 1 hr. Water (15 mL) was added to the reaction mixture, and the mixture was extracted with ethyl acetate (15 mL, 5 mL). The combined organic layer was washed with saturated aqueous sodium hydrogen carbonate solution (3 mL) and saturated brine (2 mL), and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. To the obtained residue in methanol-tetrahydrofuran mixed solution (2:1, 6 mL) was added potassium carbonate (130 mg, 0.937 mmol), and the mixture was stirred at room temperature for 14 hr. A saturated aqueous sodium hydrogen carbonate solution (15 mL) was added to the reaction mixture, and the mixture was extracted with ethyl acetate (15 mL, 5 mL). The combined organic layer was washed with saturated brine (5 mL) and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (NH silica gel, hexane/ethyl acetate=30/70→0/100), and fractions containing the desired product were concentrated under reduced pressure. Diisopropyl ether was added to the obtained residue. The obtained precipitate was collected by filtration and dried to give the title compound (490 mg, 86%) as a colorless powder.
