反应详情

To a solution of 10 g of potassium hydroxide in 200 ml of anhydrous ethanol was added 20 g of 2-(5-methyl-1,2,4-oxadiazol-3-yl)-2',4',6'-trichloroacetanilide. The mixture was heated under reflux for 10 hours. After it cooled, the mixture was acidified with 20 ml of acetic acid and concentrated to almost dryness under reduced pressure. The residue was slurried in water, collected, and dried. The crude product was stirred with 200 ml of hexane for 15 min., and the hexane solution was separated in hot ethanol and allowed to crystallize over night. There was obtained 9.6 g (48%) of 3-acetamido-1-(2,4,6-trichlorophenyl)-2-pyrazolin-5-one, mp 234°-235.5° C., and 1.5 g (12%) of 2,4,6-trichloroaniline.

1. temperatureThe mixture was heated
2. temperatureunder reflux for 10 hours
3. temperatureAfter it cooled
4. concentrationconcentrated to almost dryness under reduced pressure
5. customcollected
6. customdried
7. customthe hexane solution was separated in hot ethanol
8. customto crystallize over night