Réaction #302870

Équation de réaction

phenylisocyanate

2-aminonicotinic acid methyl ester

→

3-phenyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione

Rendement 61.2%

Solvants

pyridine

Conditions de réaction

Traitement

1. 1
   TempératureThe mixture was refluxed for 16 hours
2. 2
   AutreThe pyridine is was removed under reduced pressure
3. 3
   workup.ADDITIONthe residue was treated with 280 ml ethanol
4. 4
   TempératureThe mixture is refluxed for 10 minutes
5. 5
   TempératureUpon cooling down 3-phenyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione
6. 6
   Autrecrystallized from the medium
7. 7
   Autrewas recrystallized from methoxypropanol

Mode opératoire

17.22 g (144.6 mmol, 15.7 ml) phenylisocyanate was added to a suspenssion of 7.00 g (46.0 mmol) 2-aminonicotinic acid methyl ester in dry pyridine. The mixture was refluxed for 16 hours. The pyridine is was removed under reduced pressure and the residue was treated with 280 ml ethanol. The mixture is refluxed for 10 minutes. Upon cooling down 3-phenyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium and was recrystallized from methoxypropanol. 6.73 g (61%) 3-phenyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione was isolated (m.p. 304° C.).

Source