反应详情

A solution of methanesulphonyl chloride (60 parts) in acetone (800 parts) was added dropwise to a suspension of 5,6-dichloro-benzimidazole (94 parts) in acetone (240 parts) containing triethylamine (50 parts). A precipitate of triethylamine hydrochloride was observed and the temperature rose to 40° C. The mixture was heated under reflux for 10 minutes and then stirred at room temperature for 20 hours. On pouring into cold water (4000 parts) a solid product precipitated out, which was filtered off, washed with water, dried and recrystallised from acetone (charcoal) to give 5,6-dichloro-1-(methylsulphonyl)-benzimidazole (61 parts) as pale yellow needles, melting point 191°-193° C.

1. customrose to 40° C
2. temperatureThe mixture was heated
3. temperatureunder reflux for 10 minutes
4. customprecipitated out
5. filtrationwhich was filtered off
6. washwashed with water
7. customdried
8. customrecrystallised from acetone (charcoal)