Reaktion #4420

Reaktionsgleichung

Ethyl veratroylacetate

2-aminopyridine

→

2-(3,4-dimethoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidine

Ausbeute 150.8%

Lösungsmittel

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionThe aqueous solution was extracted with chloroform
2. 2
   Waschenwashed with water
3. 3
   Sonstigedried
4. 4
   Sonstigeevaporated
5. 5
   Sonstigeto give dark oily residue which
6. 6
   Sonstigewas chromatographed on silica gel using n-hexaneethyl acetate
7. 7
   SonstigeThe fractions were evaporated
8. 8
   Sonstigethe resulting residue was triturated with ethanol-isopropyl ether

Vorschrift

Ethyl veratroylacetate (4.5 g) was added dropwise under stirring at 60°-70° C. to a suspension of 2-aminopyridine (0.84 g) in polyphosphoric acid (13.7 g). The reaction mixture was stirred at 100° C. for 3 hrs and poured into ice-water (50 ml). The aqueous solution was extracted with chloroform, washed with water, dried and evaporated to give dark oily residue which was chromatographed on silica gel using n-hexaneethyl acetate. The fractions were evaporated and the resulting residue was triturated with ethanol-isopropyl ether to give 2-(3,4-dimethoxyphenyl)-4-oxo-4H-pyrido[1,2-a]pyrimidine (3.8 g).

Quelle