Réaction #40740

Équation de réaction

diethyl carbonate

1-ethyl-2-naphthalen-1-yl-1H-imidazole

n-BuLi

hexane

→

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

Solvants

Water

THF

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGThe resulting solution is stirred at −78° C. for 30 min
2. 2
   Températurewarmed to rt slowly
3. 3
   workup.STIRRINGstirred for an additional 30 min at rt
4. 4
   Autreto quench
5. 5
   Autrethe reaction, and THF
6. 6
   Autreis evaporated under reduced pressure
7. 7
   ExtractionThe residue is extracted with EtOAc (30 ml×2)
8. 8
   Lavagethe combined organic layers are washed with water and brine
9. 9
   Séchagedried over sodium sulfate
10. 10
    Concentrationconcentrated
11. 11
    AutreThe crude product is purified through silica gel chromatography (hexanes/EtOAc, from 8:1 to 4:1)

Mode opératoire

To a solution of 1-ethyl-2-naphthalen-1-yl-1H-imidazole (1.11 g, 5 mmol) in anhydrous THF (30 ml) at −78° C. under nitrogen is added a solution of n-BuLi in hexane (1.6 M, 3.44 ml, 5.5 mmol, 1.1 eq.) dropwise. The resulting mixture is stirred at −78° C. for 1 hr, followed by the addition of diethyl carbonate (1.77 g, 15 mmol, 3.0 eq.). The resulting solution is stirred at −78° C. for 30 min, warmed 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) 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 8:1 to 4:1) to give 3-ethyl-2-naphthalen-1-yl-3H-imidazole-4-carboxylic acid ethyl ester. LCMS 295 (M+1).

Source