To a solution of 8-(1-(4-chlorophenyl)-5-p-tolyl-1H-pyrazol-3-yl)-1,4-dioxaspiro[4.5]decan-8-ol (Reference Example 34) (931 mg, 2.19 mmol) in tetrahydrofuran (5.5 mL), 6 M hydrochloric acid (11 mL) was added, and the obtained solution was stirred at room temperature for 15 hours. The reaction solution was basified by pouring it into saturated aqueous sodium hydrogen carbonate solution, and the resulting solution was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by flash chromatography (silica gel, n-hexane/ethyl acetate) to obtain the title compound (513 mg, 1.35 mmol, 61%) as a white solid.
