Researches on antibacterial and antifungal agents. I. Analogs of nalidixic acid with a pyrrole moiety.

The synthesis and antibacterial activities of 4-hydroxyquinoline-3-carboxylic acid and 1,4-dihydro-1-ethyl-4-oxoquinoline-3-carboxylic acid containing a pyrrole or 2,5-dimethylpyrrole group at 6 position are reported. Reaction of 1-(4-aminophenyl)pyrrole or 2,5-dimethyl-1-(4-aminophenyl)-pyrrole with ethoxymethylenemalonate diethyl ester (EMME) afforded the related pyrroleanilinomethylenemalonates, which were subjected to thermal cyclization to give the required quinoline derivatives. These compounds on ethylation furnished at last the quinolonecarboxylic analogs of nalidixic acid.