5-{3-[4-(Azetidin-1-ylcarbonyl)-2-fluorophenoxy]-5-[(1S)-2-methoxy-1-methylethoxy]phenyl}-1H-pyrrole-2-carboxylic acid (126 mg, 0.27 mmol) synthesized in Example (66g) and acetohydrazide (40 mg, 0.54 mmol) were dissolved in dichloromethane (5 mL), and HATU (153 mg, 0.40 mmol) and N,N-diisopropylethylamine (70 μL, 0.40 mmol) were added at room temperature, followed by stirring under nitrogen atmosphere for 1 hour. The reaction solution was diluted with dichloromethane (60 mL), washed with 1N hydrochloric acid, a saturated aqueous sodium hydrogencarbonate solution and saturated brine, and subsequently dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (elution solvent: methanol/dichloromethane=5%) to afford the desired product (87 mg, yield 62%) as a white solid.
