Реакция #302871

Уравнение реакции

n-hexyl isocyanate

2-aminonicotinic acid methyl ester

→

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

Выход 30.8%

Растворители

pyridine

Условия реакции

Обработка

1. 1
   ТемператураThe mixture was refluxed for 24 hours
2. 2
   ДругоеThe pyridine was removed under reduced pressure
3. 3
   workup.ADDITIONthe residue was treated with 160 ml ethanol
4. 4
   ТемператураThe mixture was refluxed for 10 minutes
5. 5
   ДругоеThe crude 3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized from the medium
6. 6
   Другоеwas purified by preparative column chromatography on straight phase silica (eluent:ethyl acetate:cyclohexane 1:2)
7. 7
   Другое3-hexyl-1H-pyrido[2,3-d]pyrimidine-2,4-dione crystallized upon evaporation of the eluent

Методика

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.)

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