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 then stirred further at an external temperature of 50° C. for three hours. Ethyl acetate (50 ml) and ether (50 ml) were added thereto, and the whole was washed with water (20 ml) three times and saturated brine (30 ml) successively. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give 3-(t-butyldiphenylsiloxy)-3-(4-pyridyl)propionitrile (2.58 g, 98.9%) as a colorless oily matter.
