Lithium Hydroxide → 3-[4-(2-n-Butoxy-3,5-di-iso-propylphenyl)-5-fluorobenzo[b]thien-2-yl]-but-2-enoic acid

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Reaction Steps

A mixture of 0.450 mmol of 3-[4-(2-n-butoxy-3,5-di-iso-propylphenyl)-5-fluorobenzo[b]thien-2-yl]-but-2-enoic acid ethyl ester, 3 mL of THF, 3 mL of methanol and 1 mL of LiOH (2N aqueous) was refluxed for 2 hours. After cooling at room temperature, the mixture was acidified to pH=2 and extracted with ethyl acetate. The organic layer was dried over MgSO4 and after evaporation of the solvents, the crude acid was recrystallized from acetonitrile. 3-[4-(2-n-butoxy-3,5-di-iso-propylphenyl)-5-fluorobenzo[b]thien-2-yl]-but-2-enoic acid was isolated as a white solid. 1H-NMR (CDCl3), δ: 7.71 (dd, J=8.7, 4.4 Hz, 1H), 7.26 (t, J=16.7 Hz, 2H), 7.20 (d, J=1.8 Hz, 1H), 7.03 (d, J=1.8 Hz, 1H), 3.39 (dt, J=13.8, 6.9 Hz, 1H), 3.33 (t, J=6.3 Hz, 2H), 2.93 (dt, J=13.7, 6.8 Hz, 1H), 2.57 (s, 3H), 1.28 (m, 12H), 1.22 (m, 2H), 0.96 (m, 2H), 0.57 (t, J=7.2 Hz, 3H).

Provenance & Evidence