Boron tribromide → 3-Chloro-5-fluorophenol

Participants

Reaction Steps

A solution of 3-chloro-5-fluoroanisole (10 g, 62 mmol) in CH2Cl2 (50 mL) was cooled in a stream of argon to −70° C. under stirring. BBr3 (11.8 mL, 124 mmol) was added dropwise under vigorous stirring at −70° C. in 15 min. The reaction mixture was heated to room temperature and alkalized with the saturated NaHCO3 solution to pH ˜6. The layers were separated, and the water layer was extracted with CH2Cl2 (2×50 mL). The combined organic layer was washed with brine, dried over Na2SO4 and evaporated in vacuo to give the title compound (8 g, 88%, 54.6 mmol) as a yellow oil. 1H NMR data (dmso-d6): 10.36 (s, 1H, OH), 6.73-6.79 (m, 1H, H—Ar), 6.64-6.68 (m, 1H, H—Ar), 6.53-6.59 (m, 1H, H—Ar).

Provenance & Evidence