A solution of the compound (2.2 g) obtained in Example 114a in pyridine (40 mL) was cooled in an ice bath and 3-(trifluoromethyl)benzoyl chloride (4.16 g) was added. The reaction mixture was heated to 110-120° C. overnight, cooled to room temperature, and poured into water. The mixture was extracted with ethyl acetate. The ethyl acetate layer was separated, washed successively with 1N aqueous hydrochloric acid solution, and saturated aqueous sodium hydrogen carbonate, dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by column chromatography (carrier: silica gel, eluent: hexane-petroleum ether) to give the title compound (0.85 g) as a colorless solid.
