Pyrroloquinolones and pyrazoloquinolones as potential antibacterial agents. Synthesis and antibacterial activity

Article abstract of DOI:10.1016/S0223-5234(97)86177-6

Diethyl 1-cyclopropyl-5,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3,6-dicarboxylate 4 as a key-intermediate was synthesized via the Dieckmann reaction. The reaction of 4 with nucleophiles proceeded regioselectively at C-5. Facile cyclization between the C-5 and C-6 side chains of the resulting products gave novel pyrroloquinolones 10 and 12 and pyrazoloquinolones 15. They were converted into a series of cyclic amino-substituted pyrroloquinolones 17-21 and pyrazoloquinolones 22-24, and their in vitro antibacterial activities were tested. 1H-Pyrrolo[2,3-f]quinolone 17a and 2H-pyrrolo[3,4-f]quinolone 21a exhibited a potent in vitro antibacterial activity.