反应详情

Next, anhydrous ether (19 ml) was added to lithium aluminum hydride (257 mg, 6.77 mmol) under a nitrogen atmosphere, and the mixture was stirred under ice-cooling. A solution of 4-(4-pyridyl)-2-butanoneoxime (556 mg, 3.38 mmol) in ether (15 ml) was added dropwise to the mixture over seven minutes, then the temperature was raised to room temperature, and the whole was refluxed overnight. Further, the whole was refluxed for two days and then stirred under ice-cooling. Ethyl acetate was added slowly to the reaction mixture, and then a 1 N aqueous sodium hydroxide solution was added thereto (first slowly, total 20 ml). Chloroform (80 ml) was added thereto, and an insoluble matter was filtered out with Celite. Layers were separated, and the chloroform layer was concentrated under reduced pressure. The residue was combined with the aqueous layer, tetrahydrofuran (20 ml) was added thereto, and the whole was stirred at room temperature. Di-t-butyl carbonate (1.48 g, 6.78 mmol) was added thereto, and the whole was stirred overnight. The whole was extracted with chloroform (50 ml), and the organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. A 4 N solution of hydrogen chloride in ethyl acetate (3 ml) and ethanol (1 ml) were added to the residue, and the mixture was stirred at room temperature. After three hours, the reaction mixture was concentrated under reduced pressure. Chloroform (5 ml), methanol (5 ml) and triethylamine (1 ml) were added to the residue, and the mixture was concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography to give 161 mg (32%) of the titled compound as a brown oily matter.

1. temperaturecooling
2. temperaturethe whole was refluxed overnight
3. temperatureFurther, the whole was refluxed for two days
4. stirringstirred under ice-
5. temperaturecooling
6. filtrationan insoluble matter was filtered out with Celite
7. customLayers were separated
8. concentrationthe chloroform layer was concentrated under reduced pressure
9. additionwas added
10. stirringthe whole was stirred at room temperature
11. stirringthe whole was stirred overnight
12. extractionThe whole was extracted with chloroform (50 ml)
13. dry with materialthe organic layer was dried over anhydrous magnesium sulfate
14. concentrationconcentrated under reduced pressure
15. customThe residue was purified by silica gel column chromatography
16. additionA 4 N solution of hydrogen chloride in ethyl acetate (3 ml) and ethanol (1 ml) were added to the residue
17. stirringthe mixture was stirred at room temperature
18. concentrationthe reaction mixture was concentrated under reduced pressure
19. additionChloroform (5 ml), methanol (5 ml) and triethylamine (1 ml) were added to the residue
20. concentrationthe mixture was concentrated under reduced pressure
21. customThe residue was purified by basic silica gel column chromatography