A mixture of the crude product of 4-(4-t-butylcyclohexyl)-3-(4-butylpiperazin-1-yl)benzaldehydeoxime produced in Example (101c) (269 mg), benzenesulfonyl chloride (0,11 mL, 0.862 mmol), pyridine (0.11 ml, 1.36 mmol) and tetrahydrofuran (15 mL) was refluxed for 4 hours and 30 minutes. After then distilling off tetrahydrofuran partially in the reaction mixture under reduced pressure, chloroform was added and the mixture was further refluxed for 1 hour. The reaction mixture was concentrated under reduced pressure, the obtained residue was poured into ice water, and then ethyl acetate and saturated aqueous solution of ammonium chloride were added and extraction was performed with ethyl acetate. The separated organic layer was washed twice with saturated aqueous ammonium chloride and once with brine, and then dried over anhydrous sodium sulfate. The desiccant was filtered off, and the filtrate was concentrated under reduced pressure to give a residue, which was purified by NH silica gel column chromatography (ethyl acetate/hexane, followed by ethyl acetate/methanol), to give 192 mg of the title compound as an ochre oil.
