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

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Reaction Conditions

Reaction Steps

A solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (10.00 g, 51.54 mmol) in DMF (100 mL) was cooled to 0° C. in an ice bath and treated with sodium hydride (60% dispersion in oil) (3.092 g, 77.30 mmol) in one portion. The reaction mixture was stirred at 0° C. for 2 minutes, then at ambient temperature for 30 minutes. The reaction mixture was cooled to 0° C. and (2-(chloromethoxy)ethyl)trimethylsilane (11.82 mL, 67.00 mmol) was added. The reaction mixture was warmed to ambient temperature and allowed to stir overnight. The reaction mixture was poured into aqueous saturated ammonium chloride (100 mL) containing ice (approximately 100 mL) and stirred until the ice melted. After the ice melted, the cold mixture was extracted with ethyl acetate. The combined organic extracts were washed with water, brine, dried over MgSO4, and concentrated under reduced pressure to afford the title compound (14.45 g, 44.56 mmol, 86.46% yield). MS (apci) m/z=325.0 (M+H).

Provenance & Evidence