Trimethyl borate → (4-Chloro-3-methoxyphenyl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To 4-bromo-1-chloro-2-methoxybenzene (2.2 g, 9.9 mmol) in toluene/THF (16/6 mL) at −78° C. was added n-butyl lithium (8.7 mL, 1.6 M in hexane, 14 mmol) dropwise. The reaction was stirred at −78° C. for 30 min, then trimethylborate (2.2 mL, 19.8 mmol) was added. The reaction was allowed to warm to rt and stirred overnight and then quenched with 1 M HCl (15 mL). The organic layer was separated and dried over sodium sulfate. The solvent was removed and the crude product was purified by flash column chromatography to give 25A (1.2 g, 65% yield) as a white solid. 1H NMR (400 MHz, CDOD3) δ ppm 3.87 (m, 3H) 7.11 (d, J=7.83 Hz, 1H) 7.20 (s, 1H) 7.29 (d, J=7.83 Hz, 1H).

Provenance & Evidence