Reacción #302871

Ecuación de reacción

n-hexyl isocyanate

2-aminonicotinic acid methyl ester

→

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

Rendimiento 30.8%

Disolventes

pyridine

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture was refluxed for 24 hours
2. 2
   OtroThe pyridine was removed under reduced pressure
3. 3
   workup.ADDITIONthe residue was treated with 160 ml ethanol
4. 4
   TemperaturaThe mixture was refluxed for 10 minutes
5. 5
   OtroThe crude 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium
6. 6
   Otrowas purified by preparative column chromatography on straight phase silica (eluent:ethyl acetate:cyclohexane 1:2)
7. 7
   Otro3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized upon evaporation of the eluent

Procedimiento

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.)

Fuente