Boron tribromide → 5-Bromo-2-chlorophenol

Participants

Reaction Steps

To 50 mL of a 1M solution of boron tribromide in CH2Cl2 at 0° C. was added 5.71 g (25.8 mmol) of 5-Bromo-2-chloroanisole. After 2 hours, the reaction was allowed to warm to room temperature. After 5 hours, the solution was cooled to 0° C., and quenched with methanol. The resulting solution was partitioned between water and ethyl acetate, and the phases were separated. The aqueous phase was back-extracted once with ethyl acetate. The combined ethyl acetate phases were diluted with one volume of ether, and were extracted twice with 1M NaOH. The combined basic aqueous phases were acidified with 12M HCl, and were extracted once with ethyl acetate. The final ethyl acetate phase was washed once with brine, dried over MgSO4, filtered, and concentrated to give the phenol as a tan solid. 1H NMR (DMSO-d6, 400 MHz) 10.66 (s, 1H), 7.27 (d, 1H), 7.08 (s, 1H), 6.95 (d, 1H) ppm.

Provenance & Evidence