To a mixture of the crude product of 4-(4-t-butylcyclohexyl)-3-(4-butylpiperazin-1-yl)benzaldehyde produced in Example (101b) (247 mg), hydroxylammonium chloride (134 mg, 1.93 mmol) and ethanol (10 mL) were added sodium acetate (193 mg, 2.35 mmol) and water (1.5 mL), followed by stirring for 2 hours at room temperature. The reaction mixture 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 with brine and then dried over anhydrous sodium sulfate. The desiccant was filtered off, and the filtrate was concentrated under reduced pressure to give 271 mg of a crude product of the title compound as a light yellow solid. This product was directly used without purification for the following reaction.
