反应详情

Compound 22.2 (4.20 g, 13.66 mmol) in pyrdine (40 mL, 0.33 M) was cooled to 0° C. and treated with benzoyl chloride (12.68 mL, 109.3 mmol) The mixture was warmed to room temperature and stirred for 16 h. The solvent was removed in vacuo and the residue was treated with 2.5 N KOH (40 mL) in pyridine (40 mL) and stirred for 20 min. The mixture was cooled to 0° C. and AcOH was added (6 mL). The solvent was removed in vacuo and the residue was dissolved in EtOAc (150 mL) and washed with H2O (100 mL), saturated NaHCO3 (2×100 mL), and brine (100 mL). The organic layer was dried over Na2SO4, filtered, and concentrated under reduced pressure to afford compound 22.3 (2.74 g, 49% yield) as a white solid: 1H NMR (CDCl3, 300 MHz) 9.02 (br s, 1H), 8.80 (s, 1H), 8.55 (s, 1H), 7.97 (d, J=7.5 Hz, 2H), 7.62 (app t, J=7.5 Hz, 1H), 7.52 (t, J=7.5 Hz, 2H), 6.65 (s, 1H), 5.25 (m, 1H), 5.07 (d, J=6.0 Hz, 1H), 4.99 (br s, 1H), 4.53 (m, 1H), 3.91 (m, 1H), 3.77 (m, 1H), 1.61 (s, 3H), 1.35 (s, 3H); MS (ESI) m/z 412 [M+H]+.

1. customThe solvent was removed in vacuo
2. additionthe residue was treated with 2.5 N KOH (40 mL) in pyridine (40 mL)
3. stirringstirred for 20 min
4. temperatureThe mixture was cooled to 0° C.
5. additionAcOH was added (6 mL)
6. customThe solvent was removed in vacuo
7. dissolutionthe residue was dissolved in EtOAc (150 mL)
8. washwashed with H2O (100 mL), saturated NaHCO3 (2×100 mL), and brine (100 mL)
9. dry with materialThe organic layer was dried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure