反应详情

温度

90 °C

To a solution of malonic acid (80 g, 0.79 mol) and methylurea (50 g, 0.68 mol) in 180 ml of acetic acid at 70° C., acetic anhydride (130 ml, 1.37 mol) is added slowly. After the completion of the addition, the reaction mixture is stirred at 90° C. for 3 hours, and then cooled to room temperature. The solvent is removed under reduced pressure, and the residue is treated with 350 mL of ethanol to precipitate out yellowish solid. The solid is recrystallized from ethanol to give 63.1 g product as crystalline solids (Yield: 65.8%). m.p.=131.2-133.1° C. [Lit.1: m.p.=130-131.5° C.].

1. additionAfter the completion of the addition
2. temperaturecooled to room temperature
3. customThe solvent is removed under reduced pressure
4. additionthe residue is treated with 350 mL of ethanol
5. customto precipitate out yellowish solid
6. customThe solid is recrystallized from ethanol