| 摘要 |
An improved process for the preparation of 7-substituted amino-1-alkyl- or cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids is described where tetrafluorobenzoyl chloride is converted in three operations via 1-alkyl or 1-cycloalkyl-1,4-dihydro-6,7,8-trifluoro-4-oxoquinoline-3-carbonitrile which in a separate step or in situ is displaced and hydrolyzed to the desired product. |
