Boron tribromide → 7-Bromomethyl-5-methoxy-2-(4-methoxy-phenyl)-benzofuran

Participants

Reaction Conditions

Reaction Steps

Benzyl Alcohol 3 (1.02 g, 3.59 mmole) was dissolved in dichloromethane (70 mL) and cooled to −78° C. in an dry ice/acetone bath. Boron tribromide (1.0 M in dichloromethane), (3.95 mL, 3.95 mmole) was added drop wise over 15 minutes. After 30 minutes, the light orange solution was allowed to come to room temperature and reacted for an additional four hours. The solution was concentrated and added to saturated sodium bicarbonate, and extracted with ethyl acetate. Organic layers were combined and washed with water and brine, dried over magnesium sulfate. The organic phases were concentrated and the residue was loaded on to silica gel and chromatographed with silica gel (hexanes:ethyl acetate, 9:1) to afford 2.91 g (81%) of benzyl bromide17 as a white solid: Mp=158–160° C.; 1H NMR (DMSO-6) δ 7.88(d, 2 H, J=8.8 Hz), 7.23 (s, 1 H), 7.11 (d, 2 H, J=2.5 Hz), 7.09 (d, 2 H, J=8.9 Hz), 6.99 (d, 1 H, J=2.5 Hz), 4.96 (s, 2 H), 3.82 (s, 3 H), 3.80 (s, 3 H).

Provenance & Evidence