Реакция #170669

Уравнение реакции

sodium hydroxide

1-phenyl-4,5-dihydro-1H-pyrazol-3-ylamine

→

titled compound

Выход 24.7%

1-Phenyl-1H-pyrazol-3-ylamine

Выход 24.7%

Растворители

N,N-dimethylformamide

1,4-dioxane

Условия реакции

Обработка

1. 1
   Температураcooling over 20 minutes
2. 2
   Температураcooling over 25 minutes
3. 3
   workup.STIRRINGthe mixture was stirred at room temperature for 1 hour
4. 4
   ФильтрацияThe mixture was filtered through Celite
5. 5
   Другоеto remove the insoluble substance
6. 6
   Промывкаeluted with ethyl acetate (250 ml×3)
7. 7
   Экстракцияthe filtrate was extracted with ethyl acetate (300 ml)
8. 8
   ПромывкаThe resulting organic layer was sequentially washed with water (300 ml)
9. 9
   ЭкстракцияThe separated aqueous layer was extracted twice with ethyl acetate (300 ml)
10. 10
    workup.ADDITIONTo the combined organic layer were added anhydrous sodium sulfate (50 g) and silica gel (50 g)
11. 11
    workup.STIRRINGthe mixture was stirred at room temperature for 1 hour
12. 12
    ФильтрацияThis mixture was filtered with silica gel (100 g) on Celite
13. 13
    Промывкаsubjected to elution with ethyl acetate (250 ml×3)
14. 14
    КонцентрированиеThe filtrate was concentrated
15. 15
    workup.ADDITIONdiisopropyl ether (500 ml) was added to the resulting residue
16. 16
    workup.STIRRINGthe mixture was stirred at room temperature
17. 17
    ФильтрацияThe insoluble substance was collected by filtration
18. 18
    Промывкаwashed twice with diisopropyl ether (100 ml)
19. 19
    Другоеdried under reduced pressure

Методика

To a solution of 1-phenyl-4,5-dihydro-1H-pyrazol-3-ylamine (50.0 g) in N,N-dimethylformamide (150 ml) and 1,4-dioxane (500 ml) was added 3,4,5,6-tetrachloro-1,4-benzoquinone (84.0 g) under ice-cooling over 20 minutes, and the mixture was stirred at room temperature for 4.5 hours. To the reaction mixture was added a 2M aqueous solution of sodium hydroxide (400 ml) under ice-cooling over 25 minutes, and the mixture was stirred at room temperature for 1 hour. The mixture was filtered through Celite to remove the insoluble substance, and eluted with ethyl acetate (250 ml×3), and then the filtrate was extracted with ethyl acetate (300 ml). The resulting organic layer was sequentially washed with water (300 ml) and a saturated aqueous solution of sodium chloride (300 ml). The separated aqueous layer was extracted twice with ethyl acetate (300 ml). To the combined organic layer were added anhydrous sodium sulfate (50 g) and silica gel (50 g), and the mixture was stirred at room temperature for 1 hour. This mixture was filtered with silica gel (100 g) on Celite, and subjected to elution with ethyl acetate (250 ml×3). The filtrate was concentrated, and diisopropyl ether (500 ml) was added to the resulting residue, and the mixture was stirred at room temperature. The insoluble substance was collected by filtration, washed twice with diisopropyl ether (100 ml), and dried under reduced pressure to give the titled compound (12.2 g).

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