METHOD OF OBTAINING DERIVATIVES OF 1-METHYLAMINOQUINOLINECARBOXYLIC ACID OR THEIR SALTS CONNECTING PHARMACEUTICALLY ACCEPTABLE ACIDS

PCT No. PCT/HU86/00067 Sec. 371 Date Jun. 24, 1987 Sec. 102(e) Date Jun. 24, 1987 PCT Filed Dec. 9, 1986 PCT Pub. No. WO87/03586 PCT Pub. Date Jun. 18, 1987.The present invention relates to a process for the preparation of compounds of the general Formula I I and pharmaceutically acceptable salts thereof (wherein R stands for piperazinyl or 4-methyl-piperazinyl) which comprises reacting a compound of the general Formula II II (wherein R1 and R2 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) with a piperazine of the general Formula III III (wherein R3 represent hydrogen or methyl) or a salt thereof, hydrolysing the compound of the general Formula IV IV thus obtained (wherein R, R1 and R2 are as stated above) without or after hydrolysis and if desired converting the compound of the general Formula I thus obtained into a salt thereof or setting free the same from its salt. The compounds of the general Formula I are known antibacterial agents. The advantage of the process of the present invention is that it enables the preparation of the compounds of the general Formula I in a simple manner, with high yields and in a short reaction time.