反应详情

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.

1. additionwas added sequentially
2. temperatureheated
3. temperatureat reflux temperature
4. customwith continuous removal of water using a Dean-Stark apparatus for 2 h
5. customSolvent was evaporated to dryness under reduced pressure
6. customThe residue obtained
7. customwas purified by silica gel chromatography
8. washeluted with hexane-ethyl acetate (1:1)