反应详情

温度

100 °C

To 1-(4-bromo-phenyl)-3-cyclopropyl-urea 31 (12.9 g) obtained in Step 1 was added acetic anhydride (25.8 ml), malonic acid 4 (5.79 g) was added under a nitrogen atmosphere, and the mixture was stirred at 100° C. for 3 hrs. After allowing to cool to room temperature, the reaction mixture was concentrated under reduced pressure. Diethyl ether-ethanol [4:1 (volume ratio), 100 ml] was added to the residue and, after stirring, the crystals were collected by filtration and dried to give 1-(4-bromo-phenyl)-3-cyclopropyl-pyrimidine-2,4,6-trione 32 (11.9 g, yield 73%) as pale-yellow crystals.

1. additionwas added under a nitrogen atmosphere
2. temperatureto cool to room temperature
3. concentrationthe reaction mixture was concentrated under reduced pressure
4. additionDiethyl ether-ethanol [4:1 (volume ratio), 100 ml] was added to the residue
5. stirringafter stirring
6. filtrationthe crystals were collected by filtration
7. customdried