Synthesis and biological activity of 1,5-dihydropyridazino-[3,4-b]quinoxalines and a new class of quinolones

A new class of quinolones, 1,4-dihydro-4-oxopyridazino3,4-b]quinoxaline-3-carboxylic acids and related compounds, were synthesized via oxidation of 1,5-dihydropyridazino3,4-b]quinoxalines obtained from 2-hydrazinoquinoxaline 4-oxides. Some of the 1,5-dihydropyridazino3,4-b]quinoxalines, 1,4-dihydro-4-oxopyridazino3,4-b]quinoxaline-3-carboxylic acids, and related compounds showed biological activity.