Reaktion #531843

Reaktionsgleichung

lithium aluminum hydride

lithium aluminum hydride

3,7-dibromodibenzothiophene dioxide

ether

hydrochloric acid

→

3,7-dibromodibenzothiophene

Ausbeute 48.1%

Lösungsmittel

Chloroform

Water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe resulting mixture is refluxed
2. 2
   workup.STIRRINGthe mixture is thoroughly stirred
3. 3
   Sonstigethe organic layer is separated
4. 4
   ExtraktionThe aqueous layer is further extracted with chloroform (200 ml×2)
5. 5
   Extraktionthe chloroform extract
6. 6
   Waschenthe combined organic layer is washed with water (200 ml) and saturated brine (200 ml)
7. 7
   Trocknendried over calcium chloride
8. 8
   workup.DISTILLATIONThe solvent is distilled off
9. 9
   Sonstigecolorless crystals thus obtained
10. 10
    Sonstigeare recrystallized from ethyl acetate+ethanol (16:3)

Vorschrift

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.

Quelle