To a solution of the methyl 5-{[(2,4-dimethoxybenzyl)(pyrimidin-4-yl)amino]sulfonyl}-4-fluoro-2-{[(1S*,2R*)-2-(1-methyl-1H-pyrazol-5-yl)cyclopentyl]oxy}benzoate (83.3 mg, 0.133 mmol) prepared in Example 62b in THF (2.0 mL), a 5 M aqueous sodium hydroxide solution (2.0 mL) was added, and the reaction solution was stirred at room temperature for 15 hours. To the reaction solution, 1 M hydrochloric acid (10 mL) was added with cooling on ice, followed by extraction with ethyl acetate. The thus obtained organic layer was washed with saturated saline. The organic layer was dried over anhydrous sodium sulfate and vacuum concentrated, and THF (2.0 mL) was added to the obtained residue. To the reaction solution, 4-methylmorpholine (20.0 μL, 0.183 mmol) and isobutyl chloroformate (23.0 μL, 0.183 mmol) were added in that order with cooling on ice, and the mixture was stirred for 1 hour with cooling on ice. Then, 28% ammonia water (2.0 mL) was added thereto, and the mixture was stirred at room temperature for 12 hours. To the reaction solution, saturated saline was added, followed by extraction with ethyl acetate. The thus obtained organic layer was washed with saturated saline. The organic layer was dried over anhydrous sodium sulfate and vacuum concentrated, and the obtained residue was purified with silica gel chromatography (dichloromethane/methanol=85:15) to yield the title compound (64.2 mg, 86%) as a colorless amorphous solid.
