반응 #40737

반응 방정식

4,5-dibromo-1-ethyl-2-naphthalen-1-yl-1H-imidazole

n-BuLi

hexane

n-BuLi

hexane

chlorotrimethylsilane

diethyl carbonate

tetrabutylammonium fluoride

→

1-ethyl-2-naphthalen-1-yl-1H-imidazole-4-carboxylic acid ethyl ester

용매

THF

THF

Water

THF

반응 조건

후처리

1. 1
   workup.STIRRINGThe resulting solution is stirred at −78° C
2. 2
   workup.WAITAfter 1 hour
3. 3
   workup.STIRRINGThe resulting mixture is stirred at −78° C. for 1 hr
4. 4
   workup.STIRRINGThe resulting solution is stirred at −78° C. for 30 min
5. 5
   기타waned to rt
6. 6
   workup.STIRRINGstirred for an additional 30 min at rt
7. 7
   기타to quench
8. 8
   기타the reaction, and THF
9. 9
   기타is evaporated under reduced pressure
10. 10
    추출The residue is extracted with EtOAc (30 ml×2)
11. 11
    세척The combined organic layers are washed with water and brine
12. 12
    건조dried over sodium sulfate
13. 13
    농축concentrated
14. 14
    기타to give the crude product, which
15. 15
    workup.STIRRINGthe resulting mixture is stirred at it for 2 hr
16. 16
    기타The solvent is evaporated under reduced pressure
17. 17
    workup.ADDITIONthe residue is diluted with water (30 ml)
18. 18
    추출The mixture is extracted with EtOAc (30 ml×3)
19. 19
    세척washed with water and brine
20. 20
    건조dried over Na2SO4
21. 21
    농축concentrated
22. 22
    기타Purification through silica gel chromatography (hexanes/EtOAc, from 8:1 to 4:1)

실험 절차

To a solution of 4,5-dibromo-1-ethyl-2-naphthalen-1-yl-1H-imidazole (3.80 g, 10 mmol) in anhydrous THF (60 ml) at −78° C. under nitrogen is added a solution of n-BuLi in hexane (1.6 M, 6.88 ml, 11 mmol, 1.1 eq.) dropwise. The resulting mixture is stirred at −78° C. for 1 hr, after which chlorotrimethylsilane (1.188 g, 11 mmol, 1.1 eq.) is added. The resulting solution is stirred at −78° C. After 1 hour, n-BuLi in hexane (1.6 M, 6.88 ml, 11 mmol, 1.1 eq.) is added dropwise. The resulting mixture is stirred at −78° C. for 1 hr, followed by the addition of diethyl carbonate (3.54 g, 30 mol, 3.0 eq.). The resulting solution is stirred at −78° C. for 30 min, waned to rt slowly, and stirred for an additional 30 min at rt. Water (30 ml) is added to quench the reaction, and THF is evaporated under reduced pressure. The residue is extracted with EtOAc (30 ml×2). The combined organic layers are washed with water and brine, dried over sodium sulfate, and concentrated to give the crude product, which is dissolved in THF (30 ml). To this THF solution is added tetrabutylammonium fluoride (1.1 eq.), and the resulting mixture is stirred at it for 2 hr. The solvent is evaporated under reduced pressure, and the residue is diluted with water (30 ml). The mixture is extracted with EtOAc (30 ml×3), washed with water and brine, dried over Na2SO4 and concentrated. Purification through silica gel chromatography (hexanes/EtOAc, from 8:1 to 4:1) affords 1-ethyl-2-naphthalen-1-yl-1H-imidazole-4-carboxylic acid ethyl ester. LCMS 295 (M+1).

출처