反応 #45446

反応方程式

sodium bicarbonate

5-bromo-2-hydroxy-benzaldehyde

hydroxylamine-O-sulfonic acid

→

desired product

5-bromo-1,2-benzisoxazole

溶媒

water

dichloromethane

ethanol

反応条件

後処理

1. 1
   workup.STIRRINGThe solution was stirred at 0° C. for 30 minutes
2. 2
   その他The organic layer was removed
3. 3
   抽出the aqueous layer was extracted with dichloromethane
4. 4
   workup.ADDITIONThe aqueous layer was treated with additional dichloromethane (50 mL)
5. 5
   workup.STIRRINGstirring
6. 6
   workup.WAITwas continued for one hour
7. 7
   その他The layers were separated
8. 8
   抽出the aqueous layer was extracted with dicloromethane
9. 9
   洗浄The combined organic layers were washed with brine
10. 10
    乾燥dried (MgSO4)
11. 11
    濃縮concentrated
12. 12
    その他The concentrate was recrystallized from ethanol

実験手順

A solution of 5-bromo-2-hydroxy-benzaldehyde (2.0 g, 10 mmol) in ethanol (10 mL) at room temperature was treated with hydroxylamine-O-sulfonic acid (1.69 g, 15 mmol), stirred for 20 minutes, diluted with dichloromethane (50 mL), cooled to 0° C. and treated with a solution of sodium bicarbonate (3 g) in water (25 mL). The solution was stirred at 0° C. for 30 minutes. The organic layer was removed and the aqueous layer was extracted with dichloromethane. The aqueous layer was treated with additional dichloromethane (50 mL) and stirring was continued for one hour. The layers were separated and the aqueous layer was extracted with dicloromethane. The combined organic layers were washed with brine, dried (MgSO4) and concentrated. The concentrate was recrystallized from ethanol to give 970 mg (49%) yield of the desired product. MS (ESI(−)) m/e 195.9, 197.9 (M−H)−

出典