Réaction #302871

Équation de réaction

n-hexyl isocyanate

2-aminonicotinic acid methyl ester

→

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

Rendement 30.8%

Solvants

pyridine

Conditions de réaction

Traitement

1. 1
   TempératureThe mixture was refluxed for 24 hours
2. 2
   AutreThe pyridine was removed under reduced pressure
3. 3
   workup.ADDITIONthe residue was treated with 160 ml ethanol
4. 4
   TempératureThe mixture was refluxed for 10 minutes
5. 5
   AutreThe crude 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium
6. 6
   Autrewas purified by preparative column chromatography on straight phase silica (eluent:ethyl acetate:cyclohexane 1:2)
7. 7
   Autre3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized upon evaporation of the eluent

Mode opératoire

17.46 g (137.3 mmol, 20 ml)n-hexyl isocyanate was added to a suspension of 5.31 g (34.9 mmol) 2-aminonicotinic acid methyl ester in 130 ml dry pyridine. The mixture was refluxed for 24 hours. The pyridine was removed under reduced pressure and the residue was treated with 160 ml ethanol. The mixture was refluxed for 10 minutes. The crude 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium and was purified by preparative column chromatography on straight phase silica (eluent:ethyl acetate:cyclohexane 1:2). 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized upon evaporation of the eluent. 2.66 g (310) of 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione was isolated (m.p. 166-168° C.)

Source