Trifluoroacetic acid → (E)-3-(4-((6-acetoxy-2-(2-isopropylphenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of (E)-tert-butyl 3-(4-((6-acetoxy-2-(2-isopropylphenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylate (65 mg, 0.123 mmol) in DCM (3.0 mL) at 0° C. was added TFA dropwise over 5 min. The reaction was stirred at 0° C. for 1 h after which time it was warmed to room temperature for an additional 55 min. The mixture was then diluted with DCM and concentrated in vacuo to remove both DCM and TFA. The crude material was then further azeotroped with DCM (3×) to make sure all of the TFA was removed and gave a pale yellow solid. The resulting crude material was dissolved in MeOH (3 mL) and purified by reverse phase HPLC (acidic conditions, 0.1% TFA in 45-70% CH3CN/H2O) to afford (E)-3-(4-((6-acetoxy-2-(2-isopropylphenyl)benzo[b]thiophen-3-yl)oxy)phenyl)acrylic acid (39.1 mg, 0.083 mmol, 67% yield). 1H NMR (400 MHz, CD3OD) δ ppm=7.69 (d, J=2.0 Hz, 11), 7.57 (d, J=15.9 Hz, 1H), 7.45 (dd, J=8.7, 6.4 Hz, 3H), 7.40-7.26 (m, 3H), 7.18-7.10 (m, 2H), 6.86 (d, J=8.8 Hz, 2H), 6.32 (d, J=16.0 Hz, 1H), 3.20 (p, J=6.9 Hz, 1H), 2.32 (s, 3H), 1.17 (d, J=6.9 Hz, 6H). HRMS (m/z, MH+): 473.1399.

Provenance & Evidence