反应详情

To a solution of 5-[2-(tetrahydro-2H-pyran-2-yloxy)ethyl]pyrazine-2-carboxylic acid (1.28 g) in toluene (20 mL) were added triethylamine (0.85 ml) and diphenylphosphoryl azide (1.3 mL) at room temperature, followed by stirring at room temperature for 15 minutes. The reaction solution was warmed to 90° C., followed by stirring for 30 minutes. To the reaction solution was added benzyl alcohol (1.05 mL), followed by reflux for 3 hours. After leaving it to be cooled to room temperature, water was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was sequentially washed with saturated aqueous sodium bicarbonate and saturated brine, and dried over anhydrous magnesium sulfate. After filtration and concentration, the obtained crude product was purified by silica gel column chromatography (hexane:ethyl acetate=5:1-2:1). The obtained solid was collected by filtration while washing with a solvent (hexane:diisopropyl ether=5:1), to obtain benzyl {5-[2-(tetrahydro-2H-pyran-2-yloxy)ethyl]pyrazin-2-yl}carbamate (461 mg) as a white solid.

1. temperatureThe reaction solution was warmed to 90° C.
2. stirringby stirring for 30 minutes
3. temperatureby reflux for 3 hours
4. customAfter leaving it
5. temperatureto be cooled to room temperature
6. extractionfollowed by extraction with ethyl acetate
7. washThe organic layer was sequentially washed with saturated aqueous sodium bicarbonate and saturated brine
8. dry with materialdried over anhydrous magnesium sulfate
9. filtrationAfter filtration and concentration
10. customthe obtained crude product
11. customwas purified by silica gel column chromatography (hexane:ethyl acetate=5:1-2:1)
12. filtrationThe obtained solid was collected by filtration
13. washwhile washing with a solvent (hexane:diisopropyl ether=5:1)