for the following products
1-Ethyl-6-fluoro-7-chloro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid | 1-Ethyl-7-chloro-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid | 7-Chloro-1,4-dihydro-L-ethyl-6-fluoro-4-oxo-3-quinolinecarboxylic acid | 7-Chloro-1-ethyl-6-fluoro-4-oxo-3-quinoline carboxylic acid | Norfloxacin impurity A and 7-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
