反应 #531843

反应方程式

lithium aluminum hydride

lithium aluminum hydride

3,7-dibromodibenzothiophene dioxide

ether

hydrochloric acid

→

3,7-dibromodibenzothiophene

收率 48.1%

溶剂

Chloroform

Water

反应条件

后处理

1. 1
   温度the resulting mixture is refluxed
2. 2
   workup.STIRRINGthe mixture is thoroughly stirred
3. 3
   其他the organic layer is separated
4. 4
   萃取The aqueous layer is further extracted with chloroform (200 ml×2)
5. 5
   萃取the chloroform extract
6. 6
   洗涤the combined organic layer is washed with water (200 ml) and saturated brine (200 ml)
7. 7
   干燥dried over calcium chloride
8. 8
   workup.DISTILLATIONThe solvent is distilled off
9. 9
   其他colorless crystals thus obtained
10. 10
    其他are recrystallized from ethyl acetate+ethanol (16:3)

实验过程

In a 500-ml flask, lithium aluminum hydride (4.1 g) is slowly introduced in small amounts over 50 minutes into a mixture of 3,7-dibromodibenzothiophene dioxide (20 g) and anhydrous ether (200 ml) in an ice bath, and the resulting mixture is refluxed and stirred for 2 hours. Water (200 ml) is added thereto to deactivate lithium aluminum hydride. Chloroform (200 ml) and concentrated hydrochloric acid (40 ml) are added thereto, the mixture is thoroughly stirred, and the organic layer is separated. The aqueous layer is further extracted with chloroform (200 ml×2), the chloroform extract is combined with the organic layer, and the combined organic layer is washed with water (200 ml) and saturated brine (200 ml), and dried over calcium chloride. The solvent is distilled off, and colorless crystals thus obtained are recrystallized from ethyl acetate+ethanol (16:3). Thus, 8.8 g of 3,7-dibromodibenzothiophene is obtained.

来源