Hydrochloric Acid → (2,3-Difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)phenyl)trimethylsilane

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Reaction Conditions

Reaction Steps

A 2.5 M solution of n-butyl lithium (9.5 mL, 24 mmol, 1.1 equiv) was added to a stirred solution of (2,3-difluorophenyl)trimethylsilane (4.0 g, 21 mmol, 1.0 equiv) in tetrahydrofuran (86 mL) at −78° C. The resulting very pale yellow solution was stirred at −78° C. for 1 h. 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.8 mL, 24 mmol, 1.1 equiv) was added and the pale yellow solution was allowed to slowly warm to 23° C., by allowing the dry ice/acetone bath to melt, and stirred for 20 h. The reaction mixture was diluted with water (200 mL), adjusted to approximately pH 4 using 1M hydrochloric acid, and extracted with dichloromethane (3×100 mL). The combined organic layers were dried (magnesium sulfate), gravity filtered, and concentrated by rotary evaporation to afford the title compound as a white powder (6.4 g, 96%): 1H NMR (400 MHz, CDCl3) δ 7.42 (ddd, J=7.5, 4.5, 0.5 Hz, 1H), 7.09 (ddd, J=7.5, 4, 1 Hz, 1H), 1.34 (s, 12H), 0.29 (d, J=1 Hz, 9H).

Provenance & Evidence