反应详情

1-Trifluoromethyl-3-phenyl-3-hydroxyurea (11 grams; 0.05 mol) is dissolved in a cooled (10°C) 2N aqueous sodium hydroxide solution (35 ml). Ethyl chloroformate (6 ml; 0.06 mol) is added dropwise at 10° to 15°C with stirring. Stirring is continued for a period of about 1/2 hour after the addition is completed resulting in the formation of a precipitate. The precipitate is recovered by filtration, washed with water and dried to yield 2-phenyl-4-trifluoromethyl-1,2,4-oxadiazolidine-3,5-dione.

1. stirringStirring
2. additionafter the addition
3. customis completed resulting in the formation of a precipitate
4. filtrationThe precipitate is recovered by filtration
5. washwashed with water
6. customdried