反应详情

A mixture of 2-(2,6-dichloro-4-trifluoromethylphenyl)-4,5-dicyanoimidazole (3.3 g, 0.01 mol), ethanol (10 ) and concentrated hydrochloric acid (10 ml) was stirred and heated at reflux for 24 hours. After cooling the mixture was poured into water (50 ml) and extracted with dichloromethane (2×50 ml). The combined extracts were washed with water (50 ml), dried over anhydrous sodium sulphate and evaporated to dryness. The residue was purified by mplc on silica eluted with a mixture of ethyl acetate and petroleum spirit (b.p. 60°-80° C.) (1:1) to give ethyl 5-cyano-2-(2,6-dichloro-4-trifluoromethylphenyl)-imidazole-4-carboxylate (0.35 g) m.p. 180°-181° C., after recrystallisation from a mixture of toluene and petroleum spirit (b.p. 60°-80° C.) (1:2), as a white solid.

1. temperatureheated
2. temperatureat reflux for 24 hours
3. temperatureAfter cooling the mixture
4. extractionextracted with dichloromethane (2×50 ml)
5. washThe combined extracts were washed with water (50 ml)
6. dry with materialdried over anhydrous sodium sulphate
7. customevaporated to dryness
8. customThe residue was purified by mplc on silica
9. washeluted with a mixture of ethyl acetate and petroleum spirit (b.p. 60°-80° C.) (1:1)