2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → HCID 86695955, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-bromo-4-chloro-2-fluoro-3-methylbenzene (1.70 g, 7.61 mmol) in tetrahydrofuran (45 mL) cooled to −10° C. was added isopropylmagnesium chloride (2.9 M in THF) (3.0 mL, 8.75 mmol) dropwise. The reaction mixture was stirred at −10° C. for 1 h then allowed to warm to 0° C. and stirred for 1 h. The reaction mixture was cooled to −10° C. followed by the addition of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.785 mL, 8.75 mmol) dropwise. The reaction was allowed to warm to room temperature and stirred for 14 h. The reaction mixture was quenched with 1 N aqueous sodium hydroxide solution and stirred for 10 min. The pH of the reaction was adjusted to 3 with concentrated HCl and the solution was extracted with ethyl acetate (2×30 mL). The combined organic layers were washed with water (50 mL), brine (50 mL), dried over sodium sulphate, and concentrated under reduced pressure to afford 2-(4-chloro-2-fluoro-3-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.75 g, 6.47 mmol, 85% yield) which was taken to the next step without purification. 1H NMR (400 MHz, CDCl3) δ 7.47 (m, 1 H), 7.14 (d, J=8 Hz, 1 H), 2.29 (d, J=2 Hz, 3 H), 1.36 (s, 12 H).

Provenance & Evidence