Boron tribromide → (4-Hydroxy-benzo[b]thiophen-3-yl)-acetic acid ethyl ester

Participants

Reaction Steps

To a solution of (4-Methoxy-benzo[b]thiophen-3-yl)-acetic acid ethyl ester (0.7 g, 2.8 mmol) in methylene chloride (18 mL) is added BBr3 (1.0 M, heptane, 8.6 mL, 8.6 mmol) at −20˜−30° C. The reaction mixture is allowed to warm to room temperature over 2 hrs, and TLC indicated clean conversion. The reaction is quenched by ice water, extracted with methylene chloride, dried over sodium sulfate, concentrated. Column chromatography on silica gel eluted with hexanes/ethyl acetate yields the title compound (0.4 g).

Provenance & Evidence