Synthesis and antibacterial activities of optically active substituted 1,2-dihydro-6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acids.

A series of optically active substituted 1,2-dihydro-6-oxo-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acids was prepared via optically active 2-methyl-4,5-difluoroindoline (10) and tested for antibacterial activities. Among them, (2S)-9-[(3R,1'S)-3-(1'-amino)ethyl-1-pyrrolidinyl]-8-fluoro-1,2-dihydro- 2- methyl-6-oxo-6H-pyrrolo[3,2,1-ij]-quinoline-5-carboxylic acid (19) showed potent activity against gram-positive bacteria and (2S)-8-fluoro-1,2-dihydro-2-methyl-9-(3-methyl-1-piperazinyl)-6-oxo-6H- pyrrolo[3,2,1-ij]quinoline-5-carboxylic acid (16) exhibited well balanced in vitro activity, good intravenous efficacy, and high aqueous solubility.