反应详情

A solution of the acid 324 (3.95 g, 14.1 mmol) and sulfuric acid (0.5 mL) in methanol (50 mL) was heated under reflux for 18 h, then cooled and concentrated under reduced pressure. The residue was partitioned between ethyl acetate and water; the organic phase was collected, dried (anhydrous MgSO4), filtered and concentrated to afford pure 325 (3.93 g, 95% yield). 1H NMR (400 MHz, CDCl3) δ (ppm): 7.57 (dd, J=8.2, 2.7 Hz, 1H); 7.25 (dd, J=8.6, 5.9 Hz, 1H); 7.05 (dt, J=8.2, 2.7 Hz, 1H); 3.78 (s, 2H); 3.72 (s, 3H). LCMS: (M+H) 295.0.

1. temperatureunder reflux for 18 h
2. temperaturecooled
3. concentrationconcentrated under reduced pressure
4. customThe residue was partitioned between ethyl acetate and water
5. customthe organic phase was collected
6. dry with materialdried (anhydrous MgSO4)
7. filtrationfiltered
8. concentrationconcentrated