236 mg (5.9 mmol) of sodium hydride (oily, 60%) was stirred in dimethylformamide. 691 mg (5.8 mmol) of 3-hydroxybenzonitrile was added thereto under cooling with ice. After stirring at room temperature for 30 minutes, a solution of 2 g (5.75 mmol) of 2-(4-bromophenyl)-2-(3-chloropropyl)-5,5-dimethyl-1,3-dioxane in dimethylformamide was added to the reaction mixture, and they were stirred at 100° C. overnight. Water was added to the mixture. After the extraction with ethyl acetate, the organic layer was washed with 1 N aqueous sodium hydroxide solution and saturated aqueous common salt solution and dried over anhydrous magnesium sulfate. The solvent was evaporated to obtain the crude title compound.
