反応 #531843

反応方程式

lithium aluminum hydride

lithium aluminum hydride

3,7-dibromodibenzothiophene dioxide

ether

hydrochloric acid

→

3,7-dibromodibenzothiophene

収率 48.1%

溶媒

Chloroform

Water

反応条件

後処理

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

実験手順

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.

出典