反应详情

Concentrated sulfuric acid (0.32 mL, 11.3 mmol) was added to 24.2 (4 g, 11.3 mmol) in EtOH. The mixture was heated to reflux for 15 h. After cooling, EtOH was evaporated under vacuum, and the residue was treated with EtOAc (100 mL). Saturated NaHCO3 was added to neutralize the acid. The organic layer was separated, dried with MgSO4 and concentrated to give 24.3. MS ESI (pos.) m/z: 383.1 (M+H). 1H NMR (DMSO-d6) δ 8.99 (dd, 1H); 8.24 (m, 2H); 7.77 (dd, 1H); 7.29 (d, 1H); 7.21 (d, 1H); 7.18 (d, 1H); 6.96 (dd, 1H); 4.13 (q, 2H); 3.73 (s, 5H); 1.23 (t, 3H).

1. temperatureThe mixture was heated
2. temperatureto reflux for 15 h
3. temperatureAfter cooling
4. customEtOH was evaporated under vacuum
5. additionthe residue was treated with EtOAc (100 mL)
6. additionSaturated NaHCO3 was added
7. customThe organic layer was separated
8. dry with materialdried with MgSO4
9. concentrationconcentrated