反应详情

4-(4-Chlorophenyl)pyridine 1-oxide (1.04 g, 5.07 mmol) and acetic anhydride (25 mL) were heated to reflux for 24 h. The mixture was then concentrated, and 1 N NaOH (10 mL) in MeOH (10 mL) was added. The reaction mixture was heated to reflux for 1 h, then cooled, concentrated, and purified by flash column chromatography (silica gel, methylene chloride/MeOH 100:0 to 98:2 to 95:5 then 90:10) providing the title compound (500 mg, 48%) as an off-white solid: 1H NMR (300 MHz, CDCl3) δ 11.64 (s, 1H), 7.73 (d, J=8.6 Hz, 2H), 7.54 (d, J=8.6 Hz, 2H), 7.46 (d, J=6.8 Hz, 1H), 6.60 (d, J=1.4 Hz, 1H), 6.50 (dd, J=6.9, 1.8 Hz, 1H).

1. temperatureto reflux for 24 h
2. concentrationThe mixture was then concentrated
3. addition1 N NaOH (10 mL) in MeOH (10 mL) was added
4. temperatureThe reaction mixture was heated
5. temperatureto reflux for 1 h
6. temperaturecooled
7. concentrationconcentrated
8. custompurified by flash column chromatography (silica gel, methylene chloride/MeOH 100:0 to 98:2 to 95:5