Lithium Hydroxide → (E)-3-(5-((6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl)oxy)pyridin-2-yl)acrylic acid

Participants

Reaction Steps

To a solution of (E)-methyl 3-(5-((6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl)oxy)pyridin-2-yl)acrylate (0.118 g, 0.28 mmol) in THF (2.00 mL) and water (2.00 mL) was added lithium hydroxide (1.0 M aq., 0.844 mL, 0.84 mmol) and the reaction was stirred at room temperature for 2 h. Upon completion the reaction was quenched with water, diluted with DCM and acidified to pH 1 with 1 N HCl. The mixture was extracted with DCM (3×) and the combined organic layers were passed through a phase separator and concentrated in vacuo to afford the crude product which was purified by reverse phase HPLC (acidic condition, 3% TFA in 10-100% CH3CN/H2O) to afford (E)-3-(5-((6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl)oxy)pyridin-2-yl)acrylic acid (14 mg, 0.03 mmol, 9% yield). 1H NMR (400 MHz, (CD3)2SO) δ ppm=6.66 (d, J=15.66 Hz, 1H), 6.77-6.81 (m, 2H), 6.84 (dd, J=8.59, 2.02 Hz, 1H), 7.17 (d, J=8.59 Hz, 1H), 7.22 (dd, J=8.59, 3.03 Hz, 1H), 7.31 (d, J=2.02 Hz, 1H), 7.44-7.49 (m, 2H), 7.52 (d, J=15.66 Hz, 1H), 7.64 (d, J=8.59 Hz, 1H), 8.45 (d, J=2.53 Hz, 1H). LC/MS (m/z, MH+): 406.2.

Provenance & Evidence