AMIFLOXACINE INTERMEDIATE

摘要

New 6-fluoro-7-chloro-1-methylamino-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid/boric acid anhydrides of general formula (I), (wherein R and R<1> stand for halogen; an aliphatic acyloxy group comprising 2-6 carbon atoms and optionally substituted by halogen; or an aromatic acyloxy group comprising 7-11 carbon atoms). The new compounds of general formula (I) are valuable intermediates useful in the preparation of the antibacterial agent 6-fluoro-1-methylamino-7-(4-methyl-piperazino)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid. The new compounds of general formula (I) may be prepared by reacting a compound of formula (II), or a compound of general formula (III), (wherein R<2> stands for alkyl comprising 1-4 carbon atoms) with hydrogen fluoro borate of the formula (IV), or a borone trihalide of general formula (V), (wherein X stands for fluorine, chlorine or bromine) or a complex thereof formed with an ether or a borone derivative of general formula (VI), (wherein R<3>, R<4> and R<5> stand for alkyl comprising 1-5 carbon atoms and optionally substituted by halogen or aryl comprising 6-10 carbon atoms).