Reaktion #168585

Reaktionsgleichung

malonic acid

methylurea

acetic anhydride

→

product

Ausbeute 65.8%

1-Methylpyrimidine-2,4,6(1H,3H,5H)-trione

Ausbeute 65.8%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the completion of the addition
2. 2
   Temperaturcooled to room temperature
3. 3
   SonstigeThe solvent is removed under reduced pressure
4. 4
   workup.ADDITIONthe residue is treated with 350 mL of ethanol
5. 5
   Sonstigeto precipitate out yellowish solid
6. 6
   SonstigeThe solid is recrystallized from ethanol

Vorschrift

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.].

Quelle