反应详情

In 300 ml of anhydrous tetrahydrofuran, 2.9 g (0.06 mole) of sodium hydride (50% in oil) was added thereto. The mixture was cooled below 10° C. and 7.0 g (0.06 mole) of 1-ethyl-1,3-dimethylurea was added to the mixture under stirring. The reaction was then continued at a room temperature for 15 hours. Next the reaction mixture was cooled below 0° C. and 7.1 g (0.06 mole) of phenyl isocyanate was added dropwise with stirring. The reaction was continued at about 0° C. for 3 hours, then the solvent was removed by distillation under reduced pressure to obtain a residue. Ice-water was added to the residue and 1 N-hydrochloric acid was added to make the mixture acidic, then extracted with chloroform. The extracted liquor was dried with anhydrous sodium sulfate and the solvent was removed by distillation under reduced pressure to obtain a residue. The residue was recrystallized from ethanol-petroleum ether to obtain 7.2 g (yield, 51%) of 1-ethyl-1,3-dimethyl-5-phenylbiuret having a melting point of 88.5°-90.5° C.

1. temperatureThe mixture was cooled below 10° C.
2. temperatureNext the reaction mixture was cooled below 0° C.
3. stirringwith stirring
4. waitThe reaction was continued at about 0° C. for 3 hours
5. customthe solvent was removed by distillation under reduced pressure
6. customto obtain a residue
7. additionwas added
8. extractionextracted with chloroform
9. dry with materialThe extracted liquor was dried with anhydrous sodium sulfate
10. customthe solvent was removed by distillation under reduced pressure
11. customto obtain a residue
12. customThe residue was recrystallized from ethanol-petroleum ether