反应详情

A mixture of 5-amino-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (12.47 g) and 4-chlorobutyryl chloride (12.3 g) in dry acetonitrile (200 ml) was stirred and gently warmed to effect dissolution. The solution was cooled to room temperature and stirred, after 48 hours a further quantity of 4-chlorobutyryl chloride (6.15 g) was added and stirring continued for 24 hours. The solution was evaporated under reduced pressure to give an oil which was chromatographed using dichloromethane-ethyl acetate (19:1) as eluent. Evaporation of the eluate containing the fastest moving component gave 5-(4-chlorobutyramido)-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (5 g), m.p. 173°-174° C., after crystallisation from toluene, in the form of pale yellow crystals.

1. temperaturegently warmed
2. dissolutiondissolution
3. additionwas added
4. stirringstirring
5. customThe solution was evaporated under reduced pressure
6. customto give an oil which
7. customwas chromatographed
8. customEvaporation of the eluate
9. additioncontaining the