Sodium Hydroxide → HCID 20568844, Verbindung

Reaktionsgleichung

[NH2:1][C:2]1[CH:7]=[C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:5]=[CH:4][N:3]=1.P(Cl)(Cl)(Cl)=O.[OH-:18].[Na+]>C(O)C>[CH3:4][C:5]1[N:1]=[C:2]2[CH:7]=[C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:5]=[CH:4][N:3]2[C:8](=[O:18])[C:6]=1[CH2:7][CH3:2]

Komponenten

Versuchsvorschrift

0.02 moles of 2-amino-4-ethoxycarbonylpyridine and 0.02 moles of ethyl-2-ethylacetacetate are stirred in a mixture of 10 ml. of phosphorus oxychloride and 2 g. of polyphosphoric acid at 120° C. for 2 hours. The reaction mixture is treated with 20 ml. of ethanol at 70° to 80° C., whereupon it is neutralized with a 10% (w/v) aqueous sodium hydroxide solution with ice cooling. The ethanol is evaporated, the residue is extracted with four 25-ml. portions of chloroform and the combined extracts are dried and evaporated. The evaporation residue is triturated with ether to give crystalline 2-methyl-3-ethyl-8-ethoxycarbonyl-4-oxo-4H-pyrido[1,2-a]pyrimidine, melting at 95° to 96° C. Yield: 42%. The product does not give any melting point depression when admixed with the product of Example 17.