1-[5-(2,3-dihydro-1H-inden-5-yl)-4-hydroxyl-1-methyl-1H-pyrazol-3-yl]ethanone (50 mg, 0.195 mmol) and methyl 1-(hydrazinecarbonothioyl)piperidine-4-carboxylate (51 mg, 0.234 mmol, synthesized in accordance with WO2006062240) in N,N-dimethylformamide was stirred with concentrated hydrochloric acid (24 μL, 0.293 mmol) at room temperature for 1 day. After the reaction, ethyl acetate was added, and the reaction solution was washed with saturated aqueous ammonium chloride and saturated aqueous sodium chloride. The resulting organic layer was dried over anhydrous sodium sulfate and evaporated under reduced pressure. The resulting residue was purified by medium pressure silica gel column chromatography (hexane/ethyl acetate=1/1 (v/v)→ethyl acetate) to obtain the desired product (68 mg, 77% yield).
