반응 #40742

반응 방정식

dimethyl carbonate

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

n-BuLi

hexane

→

5-chloro-3-ethyl-2-naphthalen-1-yl-3H-imidazole-4-carboxylic acid ethyl ester

용매

Water

THF

반응 조건

후처리

1. 1
   workup.STIRRINGThe resulting solution is stirred at −78° C. for 30 min
2. 2
   온도warmed to rt slowly
3. 3
   workup.STIRRINGstirred for an additional 60 min at rt
4. 4
   기타to quench
5. 5
   기타the reaction, and THF
6. 6
   기타is evaporated under reduced pressure
7. 7
   추출The residue is extracted with EtOAc (30 ml×2)
8. 8
   세척the combined organic layers are washed with water and brine
9. 9
   건조dried over sodium sulfate
10. 10
    농축concentrated
11. 11
    기타The crude product is purified through silica gel chromatography (hexanes/EtOAc, from 20:1 to 10:1)

실험 절차

To a solution of 4,5-dichloro-1-ethyl-2-naphthalen-1-yl-1H-imidazole (2.87 g, 9.86 mmol) in anhydrous THF (60 ml) at −78° C. under nitrogen is added a solution of n-BuLi in hexane (1.6 M, 6.78 ml, 10.84 mmol, 1.1 eq.) dropwise. The resulting mixture is stirred at −78° C. for 1 hr, followed by the addition of dimethyl carbonate (2.66 g, 29.6 mmol, 3.0 eq.). The resulting solution is stirred at −78° C. for 30 min, warmed to rt slowly, and stirred for an additional 60 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) and the combined organic layers are washed with water and brine, dried over sodium sulfate, and concentrated. The crude product is purified through silica gel chromatography (hexanes/EtOAc, from 20:1 to 10:1) to give 5-chloro-3-ethyl-2-naphthalen-1-yl-3H-imidazole-4-carboxylic acid ethyl ester. LCMS 315 (M+1).

출처