تفاعل #40742

معادلة التفاعل

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

المذيبات

Water

THF

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGThe resulting solution is stirred at −78° C. for 30 min
2. 2
   درجة الحرارةwarmed to rt slowly
3. 3
   workup.STIRRINGstirred for an additional 60 min at rt
4. 4
   أخرىto quench
5. 5
   أخرىthe reaction, and THF
6. 6
   أخرىis evaporated under reduced pressure
7. 7
   استخلاصThe residue is extracted with EtOAc (30 ml×2)
8. 8
   غسيلthe combined organic layers are washed with water and brine
9. 9
   تجفيفdried over sodium sulfate
10. 10
    تركيزconcentrated
11. 11
    أخرىThe crude product is purified through silica gel chromatography (hexanes/EtOAc, from 20:1 to 10:1)

الإجراء التجريبي

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).

المصدر