Reacción #531843

Ecuación de reacción

lithium aluminum hydride

lithium aluminum hydride

3,7-dibromodibenzothiophene dioxide

ether

hydrochloric acid

→

3,7-dibromodibenzothiophene

Rendimiento 48.1%

Disolventes

Chloroform

Water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe resulting mixture is refluxed
2. 2
   workup.STIRRINGthe mixture is thoroughly stirred
3. 3
   Otrothe organic layer is separated
4. 4
   ExtracciónThe aqueous layer is further extracted with chloroform (200 ml×2)
5. 5
   Extracciónthe chloroform extract
6. 6
   Lavadothe combined organic layer is washed with water (200 ml) and saturated brine (200 ml)
7. 7
   Secadodried over calcium chloride
8. 8
   workup.DISTILLATIONThe solvent is distilled off
9. 9
   Otrocolorless crystals thus obtained
10. 10
    Otroare recrystallized from ethyl acetate+ethanol (16:3)

Procedimiento

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.

Fuente