反应详情

温度

65 °C

Under a nitrogen atmosphere, to 1-(2-fluoro-4-iodophenyl)-3-methylurea 63 (87.9 g) obtained in Step 1 and malonic acid 4 (31.1 g) were added acetic anhydride (264 ml) and acetyl chloride (42.5 ml), and the mixture was stirred at 65° C. for 3 hrs. After allowing to cool to room temperature, the reaction mixture was added dropwise to water-toluene [2:1 (volume ratio), 800 ml] with stirring, and hexane (132 ml) was successively added. The precipitated crystals were collected by filtration and dried to give 1-(2-fluoro-4-iodophenyl)-3-methylpyrimidine-2,4,6-trione 64 (75.3 g, yield 69.5%) as pale-yellow crystals.

1. temperatureto cool to room temperature
2. stirringwith stirring
3. filtrationThe precipitated crystals were collected by filtration
4. customdried