| abstract |
An antibacterially active quinolone or naphthyridonecarboxylic acid derivative of the formula <IMAGE> in which R1 stands for various organic radical, R2 stands for hydrogen, alkyl having 1 to 4 carbon atoms or (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl, R3 stands for hydrogen or amino, R4 stands for a radical of the formula <IMAGE> A stands for N or C-R5, wherein R5 stands for hydrogen, halogen methyl, cyano or nitro or else together with R1 can form a bridge of the structure <IMAGE> <IMAGE> or a pharmaceutically utilizable hydrate, acid addition salt, alkali metal salt, alkaline earth metal salt, silver salt or guanidinium salt of the carboxylic acid when R2 is hydrogen. |