反応 #65388

反応方程式

4-chlorobutyryl chloride

triethylamine

4-amino-3,4-dihydro-2,2-dimethyl-6-nitro-2H-1,4-benzoxazine

→

3,4-dihydro-2,2-dimethyl-4-(2-oxo-1-pyrrolidinyl)-6-nitro-2H-1,4-benzoxazine

溶媒

methylene chloride

water

methylene chloride

反応条件

後処理

1. 1
   温度the solution was cooled on an ice bath
2. 2
   抽出extracted with chloroform
3. 3
   乾燥The organic layer was dried over anhydrous magnesium sulfate
4. 4
   濃縮concentrated under reduced pressure
5. 5
   その他The concentrate was crystallized from ether
6. 6
   その他to give 0.43 g of crude crystals of 4-chloro-N-(3,4-dihydro-2,2-dimethyl-6-nitro- 2H-1,4-benzoxazin-4-yl)butyrylamide
7. 7
   その他The crude crystals were used without purification in the next reaction
8. 8
   workup.DISSOLUTION(4) In 8 ml of N,N-dimethylformamide was dissolved 0.41 g of the above amide
9. 9
   温度the solution was cooled on an ice bath
10. 10
    workup.ADDITIONThen, 0.14 g of potassium tert-butoxide was gradually added
11. 11
    温度cooling for 1 hour
12. 12
    workup.ADDITIONafter which it was diluted with water
13. 13
    抽出extracted with ethyl acetate
14. 14
    洗浄The organic layer was washed with saturated aqueous sodium chloride solution
15. 15
    乾燥dried over anhydrous magnesium sulfate
16. 16
    ろ過filtered
17. 17
    濃縮The filtrate was concentrated under reduced pressure
18. 18
    その他crystallized from ether
19. 19
    その他The crude crystals were recrystallized from ethanol

実験手順

In 4 ml of methylene chloride was dissolved 0.35 g of 4-amino-3,4-dihydro-2,2-dimethyl-6-nitro-2H-1,4-benzoxazine and the solution was cooled on an ice bath. To this solution was added 0.16 g of triethylamine followed by dropwise addition of a solution of 0.18 ml of 4-chlorobutyryl chloride in 1.4 ml of methylene chloride. After 30 minutes, the reaction mixture was diluted with water and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The concentrate was crystallized from ether to give 0.43 g of crude crystals of 4-chloro-N-(3,4-dihydro-2,2-dimethyl-6-nitro- 2H-1,4-benzoxazin-4-yl)butyrylamide. The crude crystals were used without purification in the next reaction. (4) In 8 ml of N,N-dimethylformamide was dissolved 0.41 g of the above amide and the solution was cooled on an ice bath. Then, 0.14 g of potassium tert-butoxide was gradually added. The mixture was stirred with ice-cooling for 1 hour, after which it was diluted with water and extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure and crystallized from ether. The crude crystals were recrystallized from ethanol to give 0.16 g of 3,4-dihydro-2,2-dimethyl-4-(2-oxo-1-pyrrolidinyl)-6-nitro-2H-1,4-benzoxazine.

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