Réaction #162817

Équation de réaction

1,3-diphenylurea

malonic acid

→

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

Rendement 40.0%

Solvants

Acetic anhydride

Conditions de réaction

Traitement

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
   Températureto cool to room temperature
4. 4
   ConcentrationThe 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
   TempératureWhen the mixture was cooled to 40° C.
8. 8
   Filtrationthe crystals were collected by filtration
9. 9
   Lavagewashed with ethanol
10. 10
    Autredried

Mode opératoire

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%).

Source