4-[3-(5-benzo[b]thiophen-2-yl-2,4-dimethoxy-phenyl)-E-acryloyl]-benzoic acid → 4-[3Z-(5-Benzo[b]thien-2-yl-2,4-dimethoxyphenyl)-acryloyl]-benzoic acid

Beteiligte Stoffe

Reaktionsschritte

A solution of 4-[3E-(5-benzo[b]thien-2-yl-2,4-dimethoxyphenyl)-acryloyl]-benzoic acid (Ex-3, 101.4 mg, 0.23 mmol) in ethyl acetate (889 ml) was stirred in a well lighted-area at room temperature for 36 hours. The solution was concentrated to a yellow solid. The crude material was purified on reversed-phase preparative plates (20×20 cm, RP-18 F254, 1 mm) eluted with MEOH/ACN/H2O (45:45:10) to give 22.2 mg of the title compound, which was 86% the cis isomer by NMR analysis. 1H-NMR (DMSO-D6, major isomer) δ 7.98 (s, 4H), 7.86 (m, 2H), 7.76 (d, J=9 Hz 1H), 7.56 (s, 1H), 7.28 (m, 2H), 7.17 (d, J=12 Hz, 1H), 6.78 (d, J=12 Hz, 2H), 6.71 (s, 1H), 3.94 (s, 3H), 3.77 (s, 3H).

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