New 6-fluoro-4,12-dioxo-4,7,12,13-tetrahydro-1H-quino-[7,8-b][1,4]-benzodiazepine- 3-carboxylic acid derivatives with N-4-fluorophenyl substitution were prepared and characterized for the first time. In-vitro antimicrobial screening of targets and related intermediates revealed that the quino[7,8-b]benzodiazepines targets 11a-c have shown good antibacterial activity against gram positive strains whereas other intermediates (9 and 10) are having stronger and broader spectrum of activity. Compound