反应详情

25.4 g (0.1 mol) of 4,5-dichloro-2-trichloromethyl-imidazole prepared by treating 4,5-dichloro-2-dichloromethylene-imidazole with dry HCl at -20° to +600° C. were introduced in small portions into 200 ml of ethanol saturated with ammonia, whilst cooling with ice and stirring vigorously. The mixture was stirred for a further 30 minutes at 50° C., the constituents which had not dissolved were then filtered off and the filtrate was evaporated under reduced pressure. The combined residues were dissolved in hot water. On acidifying the solution with dilute hydrochloric acid, the reaction product precipitated out. This was filtered off, washed with water and dried. In this way 14.6 g (90% of theory) of 4,5-dichloro-2-cyano-imidazole were obtained and after recrystallization from toluene this had a melting point of 187°-189° C.

1. temperaturewhilst cooling with ice
2. stirringThe mixture was stirred for a further 30 minutes at 50° C.
3. dissolutionthe constituents which had not dissolved
4. filtrationwere then filtered off
5. customthe filtrate was evaporated under reduced pressure
6. dissolutionThe combined residues were dissolved in hot water
7. customthe reaction product precipitated out
8. filtrationThis was filtered off
9. washwashed with water
10. customdried