反应详情

To a stirred solution of 3-hydroxy-2-nitropyridine (50.0 g, 0.34 mol) in MeOH (1 L) was added 30% NaOMe in MeOH (83 mL). The solution was stirred at rt for 30 min then cooled to 0° C. and Br2 (18 mL, 0.35 mol) was added dropwise maintaining this temperature. The reaction was then stirred at 0° C. for 2 h before the addition of glacial acetic acid (10 mL). Concentration in vacuo gave crude material (119 g), to which was added acetone (2 L) and K2CO3 (153 g, 0.8 mol) followed by iodomethane (85.5 mL, 1.4 mol). After stirring at 40° C. for 4 h the reaction was cooled to rt and filtered. After concentration of the filtrate in vacuo purification by flash chromatography eluting with 3:1 heptane-EtOAc yielded the title compound (14.4 g, 61.8 mmol).

1. temperaturethen cooled to 0° C.
2. temperaturemaintaining this temperature
3. concentrationConcentration in vacuo
4. customgave crude material (119 g)
5. stirringAfter stirring at 40° C. for 4 h the reaction
6. temperaturewas cooled to rt
7. filtrationfiltered
8. customAfter concentration of the filtrate in vacuo purification by flash chromatography
9. washeluting with 3:1 heptane-EtOAc