1-ethyl-6-{3-[(2-hydroxyethyl)oxy]propyl}-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid

6-[3-({2-[(2-cyanoethyl)oxy]ethyl}oxy)propyl]-1-ethyl-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid

6-[3-({2-[(2-carboxyethyl)oxy]ethyl}oxy)propyl]-1-ethyl-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid

ethyl 6-[(1E)-3-(4-{[(1,1-dimethylethyl)oxy]carbonyl}-1-piperazinyl)-1-propen-1-yl]-1-ethyl-4-oxo-1,4-dihydro-3-quinolinecarboxylate

ethyl 1-ethyl-4-oxo-6-[(1E)-3-(1-piperazinyl)-1-propen-1-yl]-1,4-dihydro-3-quinolinecarboxylate