Trimethyl borate → (4,5-Difluoro-2-methylphenyl)boronic acid

Participants

Reaction Steps

n-Butyl lithium (4.6 mL, 11.5 mmol) is added to the mixture of 1-bromo-4,5-difluoro-2-methylbenzene (2.0 g, 9.6 mmol) and trimethyl borate (1.5 g, 14.5 mmol) in anhydrous tetrahydrofuran (30 mL), drop wise, at −78° C. over one hour, under an atmosphere of argon. The reaction mixture is stirred for another hour at the same temperature, quenched and acidified with 1 N HCl. The resulting mixture is extracted with ethyl acetate(3×). The combined organic layer is washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo.

Provenance & Evidence