反应详情

7.8 g (0.05 mol) of 1,3-dimethylbarbituric acid were suspended in 150 ml of dioxane and 5 g (0.05 mol) of triethylamine, and 11.85 g (0.05 mol) of 3-chloro-4-trifluoromethoxy-phenyl isocyanate were added. The mixture was stirred for 5 hours under reflux. When it had cooled, the reaction mixture was brought to a pH value of 3 with 2 N hydrochloric acid and was concentrated in vacuo by distilling off the solvent. The residue was mixed with 200 ml of water, filtered off, mixed with 100 ml of isopropanol, again filtered off and dried. 16.5 g (74% of theory) of 5-(3'-chloro-4'-trifluoromethoxy-phenyl-carbamoyl)-1,3-dimethyl-barbituric acid, of melting point 160° C., were obtained.

1. temperatureunder reflux
2. temperatureWhen it had cooled
3. concentrationwas concentrated in vacuo
4. distillationby distilling off the solvent
5. additionThe residue was mixed with 200 ml of water
6. filtrationfiltered off
7. additionmixed with 100 ml of isopropanol
8. filtrationagain filtered off
9. customdried