Abstract
The preparation of 4-hydroxy-1-methyl-3-(5-oxo-4,5-dihydro-1H-3-pyrazolyl)-1,2-dihydro-2-quinolinone (3) and its hydrazono-, aminomethylidene- and arylidene derivatives has been achieved. The synthesis of fused heterocyclic polynuclear systems containing quinolinone moiety is also described.