Synthesis of 1,4-dihydro-4-oxopyridazino[1,6-a]indole-3-carboxylic acids and 1,4-dihydro-4-oxopyrido[3′,2′:4,5]pyrrolo[1,2-b]-pyridazine-3-carboxylic acids as potential antibacterial agents

A few aza analogues of the quinolones have been prepared in the two families of the 1,4-dihydro-4-oxopyridazino[1,6-a]indole-3-carboxylic acids and the 1,4-dihydro-4-oxopyrido[3′,2′:4,5]pyrrolo[1,2-b]-pyridazine-3-carboxylic acids to check their antibacterial potential. One compound 6c shows antibacterial activities of the level of nalidixic acid and represents a new lead structure differing from the classical quinolones.