To a solution of 3-(imidazo[1,2-b]pyridazin-6-yloxy)aniline (113 mg, 0.50 mmol) in N-methylpyrrolidone (1.0 mL) was added 3-(trifluoromethyl)benzoyl chloride (0.151 mL, 1.00 mmol), and the mixture was stirred at room temperature for 18 hr. The reaction mixture was diluted with 1N aqueous sodium hydroxide solution, and extracted with ethyl acetate. The organic layer was washed with 1N aqueous sodium hydroxide solution and saturated brine, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/methanol=100/0→75/25), and precipitated from diisopropyl ether to give the title compound (195 mg, 98%) as a white powder.
