2-Aminopyridine → 2-(3,4-dimethoxyphenyl)-4H-pyrido[1,2-a]pyrimidin-4-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

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