MAKING OF INTERMEDIATE FOR AMIFLOXACINE PRODUCTION

PCT No. PCT/HU86/00066 Sec. 371 Date Aug. 7, 1987 Sec. 102(e) Date Aug. 7, 1987 PCT Filed Dec. 9, 1986 PCT Pub. No. WO87/03594 PCT Pub. Date Jun. 18, 1987.The invention relates to new 6-fluoro-7-chloro-1-methylamino-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid/boric acid anhydrides of the general Formula I (I) (wherein R and R1 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 the 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-quino line-3- carboxylic acid. The new compounds of the general Formula I may be prepared by reacting a compound of the Formula II (II) or a compound of the general Formula III (III) (wherein R2 stands for alkyl comprising 1-4 carbon atoms) with hydrogen fluoro borate of the Formula IV HBF4 /IV/ or a borone trihalide of the general Formula V BX3 /V/ (wherein X stands for fluorine, chlorine or bromine) or a complex thereof formed with an ether or a borone derivative of the general Formula VI (VI) (wherein R3, R4 and R5 stand for alkyl comprising 1-5 carbon atoms and optionally substituted by halogen or aryl comprising 6-10 carbon atoms).