In DMF (5 ml), a mixture of 2-(2-methylphenylamino)-6-benzoxazolylacetic acid (357 mg, 1.26 mmol), methyl 5-((2S,4S)-4-fluoro-2-pyrrolidinylmethoxy)pentanoate (295 mg, 1.26 mmol), EDC•HCl (362 mg, 1.89 mmol), HOBt (255 mg, 1.89 mmol) and triethylamine (0.88 ml, 6.30 mmol) was stirred at room temperature for 1 hour. The reaction mixture was poured in ice water (50 ml), followed by extraction with ethyl acetate. The extract was washed with ice water and saturated brine, dried over anhydrous sodium sulfate and distilled under reduced pressure to remove the solvent. The residue was purified by chromatography on a silica gel column (silica gel: 70 g), whereby from chloroform/acetone (10/1) eluate fractions, the title compound (1.05 g, 100%) was obtained as a colorless oil.
