Synthesis and antibacterial activity of new 7-(aminoazabicycloalkanyl)quinolonecarboxylic acids

Abstract A series of novel 7-[amino-substituted azabicycloalkanyl]-6-fluoro-1-substituted quinolinecarboxylic acids ( 18–53 ) have been prepared and their antibacterial activities evaluated. These compounds are characterized structurally by a new amino-substituted azabicyclo[3.3.0]octane, -[4.3.0]nonane and -[5.3.0]decane ring systems at the 7-position of quinolonecarboxylic acids. To compare the biological activities of enantiomers, (+)-7[1 S , 5 R )- and (-)-7[(1 R , 5 S )-1-aminomethyl-3-azabicyclo[3.3.0]-octan-3-yl]-1- cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxo-3-quinolonecarboxylic acid hydrochloride ( 43, 44 ) were synthesized and evaluated for antibacterial activity. Compound 43 was more potent than 44 against both Gram-positive and Gram-negative organisms. The structure-activity relationships of these quinolonecarboxylic acids are also discussed.