3-(1-Ethyl-4-hydroxy-2-oxo-2(1H)-quinolin-3-yl)-3-oxopropanoic acid (2) has been synthesized. The chemical behaviour of β-ketoacid 2 was studied towards condensation reactions with salicylaldelyde, 2-hydroxy-1-naphthaldehyde, 1-phenyl-4-hydroxy-2-oxo-quinoline-3-carboxaldehyde, 2-hydroxy-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxalde-hyde, 2-amino-3-formylchromone and its 8-allyl analog, 3-cyanochromone and its 8-allyl analog. Structures of the newly synthesized products have been deduced from their elemental analysis and spectral data.