反应详情

Lithium aluminum hydride (2.54 g) was added in small portions to a solution of ethyl 5-chloro-6-methoxypyridine-2-carboxylate (22.3 g) in tetrahydrofuran (223 mL) under ice-cooling, and the mixture was stirred at the same temperature for 10 minutes. Water was added to the reaction solution under ice-cooling. After filtration through celite, the filtrate was concentrated under reduced pressure. Brine was added to the residue, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and filtered, after which the filtrate was concentrated under reduced pressure. Manganese dioxide (116.4 g) was added to a solution of the residue in chloroform (223 mL), and the mixture was stirred at 60° C. for one hour. The reaction solution was filtered through celite, and the filtrate was concentrated under reduced pressure. The resulting residue was suspended with hexane, stirred and then filtered. The filtrate was concentrated under reduced pressure. The same operation was further repeated three times. The resulting solids were combined and dried under reduced pressure to give the title compound as a white solid (14.7 g, 83%).

1. temperaturecooling
2. temperaturecooling
3. filtrationAfter filtration through celite
4. concentrationthe filtrate was concentrated under reduced pressure
5. additionBrine was added to the residue
6. extractionfollowed by extraction with ethyl acetate
7. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
8. filtrationfiltered
9. concentrationafter which the filtrate was concentrated under reduced pressure
10. additionManganese dioxide (116.4 g) was added to a solution of the residue in chloroform (223 mL)
11. stirringthe mixture was stirred at 60° C. for one hour
12. filtrationThe reaction solution was filtered through celite
13. concentrationthe filtrate was concentrated under reduced pressure
14. stirringstirred
15. filtrationfiltered
16. concentrationThe filtrate was concentrated under reduced pressure
17. customdried under reduced pressure