CYCLOPENTENO-QUINOLONE DERIVATIVES

New cyclopenteno-quinolone derivatives, and their preparation, of the formula(I): (I) wherein R is a saturated or unsaturated aliphatic lower-hydro-carbon radical, X is a hydrogen atom or a lower alkyl radical and Y is a halogen atom or an azido, lower-alkylthio, loweralkyl-sulphonyl or nitrile radical or an unsubstituted or substituted amino group, and the pharmaceutically acceptable and pharmacologically compatible salts thereof, the derivatives in comparison with the known compounds have about the same antimicrobial action in vitro but a substantially stronger action in vivo, especially in the urinary tract.