Реакция #40742

Уравнение реакции

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

Растворители

Water

THF

Условия реакции

Обработка

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

Методика

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).

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