Hydrochloric Acid → 3-(Trimethylsilyl)phenylboronic acid

Participants

Reaction Steps

t-Butyllithium (28 cm3, 1.7 M in pentane) was added to a solution of (21) (9.65 g, 42 mmol) in ether (200 cm3) cooled in a dry ice/acetone bath, and the reaction was stirred for 30 minutes. Trimethyl borate (20 cm3, 170 mmol) was added, and the reaction was stirred for 16 hours, gradually warming to room temperature. Aqueous hydrochloric acid (3 M, 20 cm3) was added, and the reaction was stirred for a further 2 hours. Water (200 cm3) was added, and the layers were separated. The aqueous layer was extracted with ether (3×30 cm3). The combined organic extracts were washed with brine (300 cm3) and dried over magnesium sulfate, and the solvent was removed to leave a white solid. The crude product was passed through a plug of silica using light petroleum then ether as the eluent. The ether band was collected, and the solvent was removed to leave (22) as a brown solid (7.04 g, 86%).

Provenance & Evidence