تفاعل #43517

معادلة التفاعل

oxygen

tert-butyl lithium

dibenzothiophene

ethylmagnesium bromide

→

title compound

المردود 96.0%

Dibenzothiophen-4-ol

المردود 96.0%

المذيبات

THF

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةto warm to room temperature
2. 2
   workup.STIRRINGstirred like this for 16 hours
3. 3
   درجة الحرارةThe mixture was then cooled to 0° C.
4. 4
   أخرىwas again allowed to room temperature whereupon it
5. 5
   workup.STIRRINGwas stirred like this for 30 minutes
6. 6
   أخرىwas bubbled through the solution for 40 minutes
7. 7
   workup.STIRRINGThe mixture was then stirred for a further 1 hour
8. 8
   workup.ADDITIONbefore carefully pouring
9. 9
   أخرىonto crushed ice and acidifying to pH 3 with concentrated HCl
10. 10
    استخلاصThe mixture was then extracted
11. 11
    workup.ADDITIONThe organic extracts were then treated with 3M sodium hydroxide solution until pH 10
12. 12
    أخرىThe basic, aqueous layer was separated
13. 13
    أخرىto precipitate
14. 14
    workup.DISSOLUTIONThis was dissolved in diethylether (150 ml)
15. 15
    أخرىdried
16. 16
    ترشيحfiltered
17. 17
    تركيزconcentrated in vacuo
18. 18
    أخرىrecrystallised from ethanol:water (1:1) (250 ml)
19. 19
    أخرىto give a buff

الإجراء التجريبي

To a cooled (−78° C.) solution of dibenzothiophene (20.8 g, 113 mmol) in anhydrous THF (400 ml) was added tert-butyl lithium (1.7 M in pentane; 100 ml, 170 mmol). The reaction mixture was stirred at −78° C. for 1 hour and then allowed to warm to room temperature and stirred like this for 16 hours. The mixture was then cooled to 0° C. and ethylmagnesium bromide (1M in THF; 170 ml, 170 mmol) added to the amber reaction mixture in a slow stream via cannula. The reaction was again allowed to room temperature whereupon it was stirred like this for 30 minutes. A reflux condenser was attached to the reaction vessel before oxygen was bubbled through the solution for 40 minutes. The mixture was then stirred for a further 1 hour before carefully pouring onto crushed ice and acidifying to pH 3 with concentrated HCl. The mixture was then extracted using ethyl acetate (3×80 ml). The organic extracts were then treated with 3M sodium hydroxide solution until pH 10 was attained. The basic, aqueous layer was separated, acidified to pH 3 with 2M HCl which caused an oily solid to precipitate. This was dissolved in diethylether (150 ml), dried using MgSO4, filtered and concentrated in vacuo and then recrystallised from ethanol:water (1:1) (250 ml) to give a buff coloured solid that corresponded to the title compound (21.6 g, 96%) and required no further purification. m/z (LC-MS, ESP), RT=3.64 min, (M+H)=201.1

المصدر