反应详情

6-Bromo-3-hydroxypyridine-2-carbonitrile (53.8 g) obtained in Reference Example 72(1) is dissolved in acetone (550 ml), and thereto are added benzyl bromide (35.6 ml) and potassium carbonate (43.1 g). The mixture is then heated under reflux for 4 hours. After allowing to cool, water (600 ml) is added to the reaction solution, and the mixture is extracted with ethyl acetate. The aqueous layer is extracted with ethyl acetate once, and combined with the previous organic layer. The solution is washed with saturated brine and dried over sodium sulfate. The solvent is removed by evaporation under reduced pressure and the residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=5/1, followed by 3/1). The resulting residue is suspended in diethyl ether/n-hexane and the solid is collected by filtration to give the title compound (24.1 g).

1. temperatureThe mixture is then heated
2. temperatureunder reflux for 4 hours
3. temperatureto cool
4. extractionthe mixture is extracted with ethyl acetate
5. extractionThe aqueous layer is extracted with ethyl acetate once
6. washThe solution is washed with saturated brine
7. dry with materialdried over sodium sulfate
8. customThe solvent is removed by evaporation under reduced pressure
9. customthe residue is purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=5/1, followed by 3/1)
10. filtrationthe solid is collected by filtration