Synthesis and Isomeric Conversions of Several 2-Substituted 1,4-Dihydro-4-oxo-3-quinolinecarboxylic Acid Derivatives

Article abstract of DOI:10.1007/BF00633172

Ethyl ester derivatives of 6- and 8-substituted 2-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids have been synthesized by treatment of the diethyl ester of acetylmalonic acid with 2- or 4-substituted anilines.Condensation of these newly synthesized quinolinecarboxylic acid derivatives with 4-nitrobenzaldehyde resulted in the formation of 6- and 8-substituted 2-<2-(4-nitrophenyl)vinyl>-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids and ethyl esters of 6- and 8-substituted 2-<2-(4-nitrophenyl)vinyl>-4-acetoxy-3-quinolinecarboxylic acids.The tautomeric and conformational transformations of these newly synthesized compounds have also been investigated, using IR, NMR, and UV spectroscopy.