反应详情

A solution of 4-(2,4-difluorobenzyloxy)pyridine-1-oxide (13.4 g, 57 mmol) in acetic anhydride (30 mL) was stirred at reflux for 4 h. The solvent was removed under reduced pressure, the residue was diluted with 1:1 MeOH/water (60 mL), and the mixture was stirred at room temperature for 1 h. The solvent was removed under reduced pressure. Purification by flash column chromatography (silica, eluent methylene chloride to 9:1 methylene chloride/methanol) provided 4-(2,4-difluorobenzyloxy)-1H-pyridin-2-one as a light brown solid (4.2 g, 31%): 1H NMR (300 MHz, CDCl3) δ 7.43 (q, J=8 Hz, 1H), 7.23 (d, J=7 Hz, 1H), 6.91-6.87 (m, 2H), 6.02 (dd, J=8, 2 Hz, 1H), 5.97 (d, J=2 Hz, 1H), 5.03 (s, 2H).

1. temperatureat reflux for 4 h
2. customThe solvent was removed under reduced pressure
3. additionthe residue was diluted with 1:1 MeOH/water (60 mL)
4. customThe solvent was removed under reduced pressure
5. customPurification by flash column chromatography (silica, eluent methylene chloride to 9:1 methylene chloride/methanol)