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

Participants

Reaction Conditions

Reaction Steps

To a 2-dram vial containing (E)-tert-butyl 3-(4-((6-methoxy-2-(4-(trifluoromethyl)phenyl)benzo[b]thiophen-3 yl)oxy)phenyl)acrylate (59.4 mg, 0.113 mmol) in anhydrous DCM (1.5 mL) at 0° C. was added BBr3 (1.0 M in DCM, 451 μL, 0.451 mmol) dropwise. The resulting mixture was stirred at 0° C. for 1 h after which the reaction was quenched with 3 drops of water, diluted with DCM, and extracted with sat. aq. NaHCO3 (added a few drops of 2-propanol). The organic layer was dried over anhydrous MgSO4, filtered concentrated in vacuo to afford the crude material which was purified by reverse phase HPLC (neutral condition, 3% 1-propanol in 10-100% CH3CN/H2O) to afford (E)-3-(4-((6-hydroxy-2-(4-(trifluoromethyl)phenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid (33.8 mg, 0.074 mmol, 66% yield) as a white solid. 1H NMR (400 MHz, CD3OD) δ ppm=6.36 (d, J=16.17 Hz, 1H), 6.78-6.89 (m, 1H), 6.98 (d, J=8.59 Hz, 2H), 7.17-7.30 (m, 2H), 7.51-7.70 (m, 5H), 7.88 (d, J=8.08 Hz, 2H). HRMS (m/z, MH+): 457.0710.

Provenance & Evidence