Tetrahydrofuran → 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazole

Participants

Reaction Steps

Under argon atmosphere, to 20 ml of tetrahydrofuran solution containing 1.09 g (5.62 mmol) of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole was added 443 mg (11.1 mmol) of 60% sodium hydride under ice-cooling, and the mixture was stirred for 5 minutes. Then, 3 ml (17.0 mmol) of (2-trimethylsilylethoxy)methyl chloride was added dropwise to the mixture, and the mixture was reacted at room temperature for 2 hours. After completion of the reaction, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was separated, and the solutions were washed successively with water and then with a saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The obtained residue was applied to silica gel column chromatography (Eluent; hexane:ethyl acetate=9:1 (V/V)), and the fractions containing the desired compound were concentrated under reduced pressure to obtain 832 mg of the title compound as a colorless oil. (Yield: 46%)

Provenance & Evidence