Réaction #410364

Équation de réaction

2-chloro-1H-benzimidazole

tetrahydrofuran

2-chloroethyl ethyl ether

potassium bis(trimethylsilyl)amide

→

1-(2-ethoxyethyl)-2-chloro-1H-benzimidazole

Solvants

water

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAdd dropwise
2. 2
   TempératureWarm to ambient temperature
3. 3
   Températureheat to reflux
4. 4
   workup.WAITAfter 12 hours
5. 5
   Températurecool to ambient temperature
6. 6
   AutreSeparate the organic layer
7. 7
   Extractionextract the aqueous layer with dichloromethane
8. 8
   SéchageDry the combined organic layers over Na2SO4
9. 9
   Filtrationfilter
10. 10
    Autreevaporate in vacuo

Mode opératoire

Combine 2-chloro-1H-benzimidazole (15.3 g, 100 mmol) and tetrahydrofuran (300 mL). Cool to −70° C. Add dropwise, a solution of potassium bis(trimethylsilyl)amide (200 mL, 0.5 M in toluene, 100 mmol). After 30 minutes, add 2-chloroethyl ethyl ether (22.2 g, 200 mmol) and tetrabutylammonium bromide (0.5 g). Warm to ambient temperature and heat to reflux. After 12 hours, cool to ambient temperature and add water. Separate the organic layer and extract the aqueous layer with dichloromethane. Dry the combined organic layers over Na2SO4, filter, and evaporate in vacuo to give 1-(2-ethoxyethyl)-2-chloro-1H-benzimidazole.

Source