To a solution of 3′-chloro-4′-hydroxy-2′,6′-dimethylbiphenyl-3-carbaldehyde (1.41 g, 5.41 mmol) and imidazole (1.10 g, 16.2 mmol) in N,N-dimethylformamide (10 mL), was added tert-butyldimethylchlorosilane (1.22 g, 8.09 mmol) at room temperature, and the mixture was stirred at room temperature for 24 hr under nitrogen atmosphere. Water was added to the reaction mixture, and the mixture was extracted with diethyl ether. The extract was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:hexane=0:100-20:80) to give the title compound (1.78 g, yield 88%) as a colorless oil.
