4-(2-Fluoro-4-nitrophenoxy)pyridin-2-ylamine (200 mg) was dissolved in tetrahydrofuran (8 ml) under a nitrogen atmosphere, and then triethylamine (0.336 ml) and phenyl chloroformate (0.302 ml) were added dropwise thereto at room temperature, followed by stirring for 30 min. The reaction mixture was concentrated under a reduced pressure to give a residue, which was dissolved in N,N-dimethylformamide (5 ml), and then N-methyl-N-(1-methylpiperidin-4-yl)amine (0.467 ml) was added thereto at room temperature, followed by stirring for 4 hrs. The reaction mixture was partitioned between ethyl acetate and a saturated aqueous solution of ammonium chloride. The organic layer was washed with a saturated aqueous solution of ammonium chloride, water and brine in this order, and dried over anhydrous sodium sulfate. The solvent was evaporated under a reduced pressure to give a residue, which was purified by silica gel column chromatography (Fuji Silysia NH, eluent; ethyl acetate). The resultant fractions were concentrated under a reduced pressure, and dried in vacuum to provide the titled compound (245 mg, 75.5%) as a yellow solid.
