Next, imidazole (4.60 g, 67.5 mmol) and N,N-dimethylformamide (30 ml) were added to the obtained 3-hydroxy-3-(4-pyridyl)propionitrile (1.00 g, 6.75 mmol), and the mixture was stirred at room temperature. t-Butyldiphenylchlorosilane (2.23 g, 8.10 mmol) was added to the mixture, and the whole was stirred for one day and further stirred at an external temperature of 50° C. for three hours. Ethyl acetate (50 ml) and ether (50 ml) were added to the reaction mixture, the whole was washed with water (20 ml) three times and saturated brine (30 ml) successively, and the organic layer was dried over anhydrous magnesium sulfate. The organic layer was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography to give 2.58 g (98.9%) of 3-(t-butyldiphenylsiloxy)-3-(4-pyridyl)propionitrile as a colorless oily matter.
