反应详情

1-Trifluoromethyl-3-(4'-fluorophenyl)-3-hydroxyurea (11.9 grams; 0.05 mol) is dissolved in dioxane (80 ml) and mixed with 2N aqueous sodium hydroxide (30 ml). Ethyl chloroformate (5.7 ml; 0.06 mol) is then added dropwise to the mixture at 10° to 15°C, with stirring, resulting in the formation of a precipitate. The precipitate is recovered by filtration, washed with water and dried to yield 2-(4'-fluorophenyl)-4-trifluoromethyl-1,2,4-oxadiazolidine-3,5-dione.

1. customresulting in the formation of a precipitate
2. filtrationThe precipitate is recovered by filtration
3. washwashed with water
4. customdried