Reaktion #162817

Reaktionsgleichung

1,3-diphenylurea

malonic acid

→

1,3-diphenyl-pyrimidine-2,4,6-trione

Ausbeute 40.0%

Lösungsmittel

Acetic anhydride

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added under a nitrogen atmosphere
2. 2
   workup.STIRRINGThe mixture was stirred at 100° C. for 1.5 hrs
3. 3
   Temperaturto cool to room temperature
4. 4
   EinengenThe reaction mixture was concentrated under reduced pressure
5. 5
   workup.ADDITIONEthanol (500 ml) was added to the residue
6. 6
   workup.STIRRINGthe mixture was stirred at 90° C
7. 7
   TemperaturWhen the mixture was cooled to 40° C.
8. 8
   Filtrationthe crystals were collected by filtration
9. 9
   Waschenwashed with ethanol
10. 10
    Sonstigedried

Vorschrift

Acetic anhydride (290 ml) was added to 1,3-diphenylurea 18 (148 g), malonic acid 4 (81.6 g) was added under a nitrogen atmosphere, and the mixture was stirred at 90° C. for 3 hrs. The mixture was stirred at 100° C. for 1.5 hrs and allowed to cool to room temperature. The reaction mixture was concentrated under reduced pressure. Ethanol (500 ml) was added to the residue, and the mixture was stirred at 90° C. When the mixture was cooled to 40° C., the crystals were collected by filtration, washed with ethanol and dried to give 1,3-diphenyl-pyrimidine-2,4,6-trione 19 (78.0 g, yield 40%).

Quelle