Reaktion #3011

Reaktionsgleichung

hydrobromic acid

water

phenylmagnesium bromide

phenyl sulfoxide

→

triphenylsulfonium bromide

Lösungsmittel

benzene

ether

dichloromethane

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 3-necked 1 L round bottom flask equipped with a still head
2. 2
   Sonstigethe diethyl ether removed under vacuo
3. 3
   Temperaturby gently heating
4. 4
   workup.ADDITIONAdditional benzene (150 ml) was added
5. 5
   Temperatura gentle reflux under nitrogen
6. 6
   workup.ADDITIONOnce the addition
7. 7
   Temperaturthe reaction mixture was heated at
8. 8
   Temperatura gentle reflux for 3 hours
9. 9
   TemperaturThe reaction mixture was cooled (ice bath temperature)
10. 10
    SonstigeAfter separation of the layers
11. 11
    Extraktionthe organic layer extracted
12. 12
    Extraktionextracted with dichloromethane (200 ml)
13. 13
    Trocknendried (MgSO4 )
14. 14
    Einengenconcentrated in vacuo
15. 15
    Sonstigeto give the crude product as an off-white solid (14.50 g)
16. 16
    workup.ADDITIONadded
17. 17
    Sonstigeto precipitate the salt
18. 18
    TemperaturThe suspension was cooled in an ice bath for 1 hour
19. 19
    Sonstigeto collecting the salt
20. 20
    Waschenwashing with ether

Vorschrift

To a 3-necked 1 L round bottom flask equipped with a still head was added phenylmagnesium bromide (3 M in diethyl ether, 142 ml, 0.426 mol) followed by dry benzene (150 ml). The flask was connected to a water aspirator and the diethyl ether removed under vacuo by gently heating. Additional benzene (150 ml) was added and the solution brought to a gentle reflux under nitrogen. A solution of phenyl sulfoxide (17.23 g, 85.2 mmol) in benzene (100 ml) was added dropwise over 1.5 hours. Once the addition was complete, the reaction mixture was heated at a gentle reflux for 3 hours. The reaction mixture was cooled (ice bath temperature) while adding a solution of hydrobromic acid (25%, 200 ml). The resulting biphasic mixture was stirred at room temperature overnight. After separation of the layers, the organic layer extracted were combined and extracted with dichloromethane (200 ml), dried (MgSO4 ) and concentrated in vacuo to give the crude product as an off-white solid (14.50 g). The solid was taken up in the minimum mount of warm dichloromethane (100 ml) and four times the volume of ether added to precipitate the salt. The suspension was cooled in an ice bath for 1 hour prior to collecting the salt and washing with ether. In this way, triphenylsulfonium bromide was isolated as a white solid (14.40 g, 49%).

Quelle