Hydrochloric Acid → (2,2-Difluoro-1,3-dioxaindan-5-yl)boronic acid

Participants

Reaction Steps

A solution of 1.5M tert-butyllithium in pentane (130 mL, 195 mmol) in diethyl ether (500 mL) at −78° C. was treated with 5-bromo-2,2-difluoro-1,3-benzodioxole (18 g, 76 mmol) in diethyl ether (80 mL), stirred for 1 hour, treated with triisopropylborate (37 mL, 160 mmol), warmed to room temperature over 1 hour, poured into 4M NaOH (700 mL), stirred for 15 minutes, cooled, adjusted to pH 1 with concentrated HCl, and extracted with ethyl acetate. The extract was washed with brine, dried (Na2SO4), filtered, and concentrated to provide 14.7 g (95%) of the desired product. 1H NMR (DMSO-d6) δ 7.75 (m, 1H), 7.66 (m, 1H), 7.51 (m, 1H), 7.39 (m, 1H), 7.30 (m, 1H).

Provenance & Evidence