Boron tribromide → (E)-3-(4-((6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of (E)-tert-butyl 3-(4-((6-methoxy-2-(4-methoxyphenyl)-benzo[b]thiophen-3-yl)oxy)phenyl)acrylate (40 mg, 0.08 mmol) in DCM (2.5 mL) at 0° C. was added BBr3 (1.0 M in DCM, 0.33 mL, 0.33 mmol) dropwise, a solid immediately precipitated from the solution. The resulting mixture was stirred at 0° C. for 100 min after which the reaction was quenched by addition of sat. aq. NaHCO3 (4 mL) solution and a white precipitate was observed. The aqueous layer was then extracted with 5% MeOH/EtOAc (4×12 mL) and the combined organic layers were passed through a phase separator to remove water and concentrated in vacuo to afford the crude product which was dissolved in MeOH (2 mL) and purified by reverse phase HPLC (neutral condition, 3% 1-propanol in 1-100% CH3CN/H2O) to afford (E)-3-(4-((6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid (17.5 mg, 0.04 mmol, 53% yield). LC/MS (m/z, MH+): 405.0790.

Provenance & Evidence