Pyridonkarboksylsyrederivat

摘要

Known synthetic antibacterials having a condensed pyridonecarboxylic acid skeleton include quinolone derivatives having various substituents at various positions of the skeleton. The possibility of the presence of diastereoisomerism in these derivatives, however, gives rise to a mixture of at least four diastereomers having properties differing from one another, resulting in the difficulty in applying the same as such as a medicine. Under these circumstances the present invention provides an antibacterial 1-(1,2-cis-2-fluorocyclopropyl) quinolone derivative represented by general formula (I) comprising a single diastereoisomer even when there are various diastereoisomers thereof. In formula (I), R<1> represents methyl, difluoromethyl, etc.; R<2> represents a saturated nitrogenous heterocyclic group; A represents C-X<3> or nitrogen; X<1> and X<2> represent each independently halogen; and X<3> and Z represent each hydrogen, etc.