To a solution of (R)-4-methyloxazolidin-2-one (222 mg) described in Preparation Example 25 in DMF (4 mL) was added sodium hydride (84 mg) at 10° C., and the mixture was stirred for 30 min. Furthermore, [4-(5-bromo-3-methylpyridin-2-yl)piperazin-1-yl](6-fluoro-4-methylpyridin-3-yl)methanone (447 mg) described in Preparation Example 113 was added, and the mixture was stirred at 80° C. for 3 hr and at 100° C. for 3 hr. After cooling, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and the solvent was evaporated. The residue was purified by column chromatography (hexane:ethyl acetate) to give (R)-3-{5-[4-(5-bromo-3-methylpyridin-2-yl)piperazine-1-carbonyl]-4-methylpyridin-2-yl}-4-methyloxazolidin-2-one (260 mg).
