2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-(4-Chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of 1-bromo-4-chloro-2-fluoro-3-methoxybenzene (2.6 g, 10.86 mmol) in tetrahydrofuran (30 mL) cooled to −10° C. was added isopropylmagnesium bromide (4.49 mL, 13.03 mmol) dropwise and the reaction mixture was stirred at this temperature for 1 h. The reaction mixture was then warmed to 0° C. and stirred for 1 h. The reaction mixture was cooled to −10° C. and 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.215 mL, 10.86 mmol) was added dropwise. The reaction mixture was warmed to room temperature and stirring continued for 16 h. The reaction was quenched with 5% aqueous sodium hydroxide and extracted with ethyl acetate (2×25 mL). The combined organic layers were washed with brine (25 mL), dried over sodium sulphate, and concentrated under reduced pressure to afford 2-(4-chloro-2-fluoro-3-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.15 g, 7.50 mmol, 69% yield) as a brown oil. 1H NMR (400 MHz, CDCl3) δ 7.35 (m, 1H), 7.13 (m, 1H), 3.96 (s, 3H), 1.36 (s, 12H).

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