反应详情

A mixture of compound 22 (3.6 g, 14 mmol), acetic anhydride (8 mL) and pyridine (0.1 mL) was stirred at room temperature for 1 h, then concentrated in vacuo. The residue was added ice and sodium bicarbonate (until pH=7). The resulted mixture was extracted with EtOAc. The organic layers were combined, washed by brine, dried over Na2SO4, filtered and concentrated to give the title compound 23 (3.5 g, 83%). 1H NMR (400 MHz, CDCl3) δ8.79 (d, 1H, J=7.8 Hz), 7.46 (d, 1H, J=10.0 Hz), 7.38 (br s, 1H), 2.24 (s, 3H).

1. concentrationconcentrated in vacuo
2. additionThe residue was added ice and sodium bicarbonate (until pH=7)
3. extractionThe resulted mixture was extracted with EtOAc
4. washwashed by brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated