Substituted Quinolinones. Part 16. Preparation and reactions of 3-(4-hydroxy-1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)-3-oxopropanoic acid

Preparation of quinolinyl-3-oxopropanoic acid was accomplished by hydrolysis of pyranoquinolinedione, in aqueous alkaline medium. The chemical behavior of this β-keto acid towards nitrosation, coupling with a diazonium salt, esterification, condensation with 2,2-diethoxyethanamine, hydrazinolysis, Knoevenagel condensation with isatine, salicylaldehyde, 3-formylquinolones, and 3-formylchromone, was investigated. Also many of the products of these reactions were obtained using either pyranoquinolinedione 1 or β-keto acid 2, under the same conditions.