| abstract |
Antibacterial 8-cyano-1-cyclopropyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid derivatives of the formula ##STR1## in which Y represents a carboxyl group, a nitrile group, an ester group --COOR 1 or an acid amide group --CONR 2 R 3 , n X 1 represents hydrogen nitro, alkyl or halogen n X 4 can be hydrogen or halogen, or alkyl, n R 4 and R 5 , together with the nitrogen atom to which they are bonded, form a 5- or 6-membered heterocyclic ring which can additionally contain the atoms or groups --O--, --S--, --SO--, --SO 2 --, ##STR2## as ring members or the group ##STR3## can also represent a ring system of the structure ##STR4## which can optionally be substituted on the ring carbons by methyl and pharmaceutically usable hydrates, salts or esters thereof. n These compounds have a high antibacterial activity and are therefore suitable as active compounds for human and veterinary medicine. |