Benzoic Acid → 3-(3,5-Dimethoxyphenyl)-2-{4-[4-(2,4-dioxothiazolidin-5-ylidenemethyl)-phenoxy]-phenyl}-propionic acid methyl ester

Participants

Reaction Steps

To a stirred suspension of 16 (1.81 g, 4.3 mmol) in anhydrous toluene (25 mL), 2,4-thiazolidinedione (0.56 g, 4.74 mmol), benzoic acid (0.68 g, 5.60 mmol) and piperidine (0.60 mL, 6.03 mmol) was added sequentially and heated at reflux temperature with continuous removal of water using a Dean-Stark apparatus for 2 h. Solvent was evaporated to dryness under reduced pressure. The residue obtained was purified by silica gel chromatography, eluted with hexane-ethyl acetate (1:1) to yield 17 (1.82 g, 81%): mp 104-106° C.; 1H NMR (400 MHz, DMSO-d6) δ 12.53 (br s, 1H), 7.76 (s, 1H), 7.60 (d, J=8.7 Hz, 2H), 7.35 (d, J=8.7 Hz, 2H), 7.07 (d, J=4.8 Hz, 2H), 7.03 (d, J=4.8 Hz, 2H), 6.33-6.28 (m, 3H), 4.01 (t, J=7.5 Hz, 1 Hz), 3.66 (s, 6H), 3.56 (s, 3H), 3.22 (dd, J=13.8 and 8.4 Hz, 1H), 2.90 (dd, J=13.5 and 7.2 Hz, 1H); MS (EI) m/z 520[M]+; Anal. (C28H25NO7S) C: calculated, 64.73; found, 65.89; H: calculated, 4.85; found, 5.08, N: calculated, 2.70; found, 2.56.

Provenance & Evidence