Research on antibacterial and antifungal agents. III. Synthesis of 1-ethyl-1,4-dihydro-4-oxo-7-(1-pyrryl)quinoline-3-carboxylic acid and of some 6-derivatives

A new analog of nalidixic acid, 1-ethyl-1,4-dihydro-4-oxo--7-(1-pyrryl)quinoline-3-carboxylic acid, is described. When tested against gram-positive and gram-negative bacteria this compound showed many significant activities and was more active than nalidixic, piromidic and pipemidic acids. On the contrary its 6-chloro- and 6-methylderivatives lack antimicrobial activities. All new compounds here described were synthesized by standard procedures via Gould-Jacobs reaction.