Реакция #3011

Уравнение реакции

hydrobromic acid

water

phenylmagnesium bromide

phenyl sulfoxide

→

triphenylsulfonium bromide

Растворители

benzene

ether

dichloromethane

benzene

Условия реакции

Обработка

1. 1
   ДругоеTo a 3-necked 1 L round bottom flask equipped with a still head
2. 2
   Другоеthe diethyl ether removed under vacuo
3. 3
   Температураby gently heating
4. 4
   workup.ADDITIONAdditional benzene (150 ml) was added
5. 5
   Температураa gentle reflux under nitrogen
6. 6
   workup.ADDITIONOnce the addition
7. 7
   Температураthe reaction mixture was heated at
8. 8
   Температураa gentle reflux for 3 hours
9. 9
   ТемператураThe reaction mixture was cooled (ice bath temperature)
10. 10
    ДругоеAfter separation of the layers
11. 11
    Экстракцияthe organic layer extracted
12. 12
    Экстракцияextracted with dichloromethane (200 ml)
13. 13
    Сушкаdried (MgSO4 )
14. 14
    Концентрированиеconcentrated in vacuo
15. 15
    Другоеto give the crude product as an off-white solid (14.50 g)
16. 16
    workup.ADDITIONadded
17. 17
    Другоеto precipitate the salt
18. 18
    ТемператураThe suspension was cooled in an ice bath for 1 hour
19. 19
    Другоеto collecting the salt
20. 20
    Промывкаwashing with ether

Методика

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%).

Источник