Reaktion #2169815

Reaktionsgleichung

bromobenzene

magnesium

bromobenzene

(+)-β-methylbutyl-4-toluenesulfonate

sulfuric acid

→

(+)-β-methylbutylbenzene

Ausbeute 64.8%

Lösungsmittel

ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reagent was cooled
2. 2
   workup.ADDITIONWhen the addition
3. 3
   Temperaturrefluxed for two hours
4. 4
   workup.WAITleft
5. 5
   workup.WAITto stand overnight
6. 6
   Sonstigewas formed
7. 7
   SonstigeThe layers were separated
8. 8
   ExtraktionThe aqueous layer was extracted with ether (3×250ml)
9. 9
   Waschenthe combined organic layers were washed with sodium bicarbonate solution, water
10. 10
    Trocknendried over anhydrous sodium sulfate
11. 11
    SonstigeThe solvent was evaporated
12. 12
    workup.DISTILLATIONthe residue was steam-distilled
13. 13
    workup.DISTILLATIONFractional distillation of the crude product at reduced pressure

Vorschrift

Phenylmagnesium bromide-ether solution was prepared from bromobenzene (64.5g, 0.41m), magnesium turnings (9.85g, 0.41m), and anhydrous ether (500ml). The reagent was cooled and (+)-β-methylbutyl-4-toluenesulfonate (200g, 0.82m) in ether (800ml) was added in drops. When the addition was complete, the reaction mixture was stirred for two hours, refluxed for two hours and left to stand overnight. Aqueous sulfuric acid was added until a clear solution was formed. The layers were separated. The aqueous layer was extracted with ether (3×250ml), and the combined organic layers were washed with sodium bicarbonate solution, water and dried over anhydrous sodium sulfate. The solvent was evaporated and the residue was steam-distilled. Fractional distillation of the crude product at reduced pressure yielded (+)-β-methylbutylbenzene (38.7g, 64.8%), bp. 74°-77° C at 12 mm pressure.

Quelle