Citric Acid → (E)-methyl 3-(4-((2-bromo-6-hydroxybenzo[b]thiophen-3-yl)oxy)phenyl)acrylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (E)-methyl 3-(4-((2-bromo-6-methoxybenzo[b]thiophen-3-yl)oxy)phenyl)acrylate (2.4 g, 5.72 mmol) in DCM (20 mL) at room temperature was added BBr3 (1.0 M in Heptane, 17.17 mL, 17.17 mmol) dropwise. The resulting mixture was stirred at room temperature for 2 h after which time an aqueous buffer (pH 7.4, made from citric acid and dibasic sodium phosphate, 10 mL), cooled to 0° C. was slowly added into the reaction. The resulting mixture was then diluted with DCM (30 mL) and stirred at room temperature for 1 h. The phases were then separated and the organic phase was dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The crude material was purified by column chromatography (SiO2, 0-100% EtOAc/Heptane) to afford (E)-methyl 3-(4-((2-bromo-6-hydroxybenzo[b]thiophen-3-yl)oxy)phenyl)acrylate (1.6 g, 3.95 mmol, 69% yield) as a pale yellow solid and (E)-3-(4-((2-bromo-6-hydroxybenzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid (370 mg, 0.946 mmol, 17% yield) as a yellow solid.

Provenance & Evidence