| 摘要 |
<p>The invention relates to a new process for the preparation of compounds of general formula (I) (wherein R?1 and R3¿ stand for hydrogen or C¿1-4? alkyl, R?2¿ stands for C¿1-4? alkyl, R?4, R5 and R6¿ stand for hydrogen or halogen) and pharmaceutically acceptable salts thereof, which comprises reacting a compound of general formula (II) (wherein R stands for halogen or an aliphatic acyloxy group containing 2 to 6 carbon atoms or an aromatic acyloxy group containing 7 to 11 carbon atoms, and R?4, R5, R6¿ have the meanings defined above) with a piperazine derivative of general formula (III) (wherein R?1, R2 and R3¿ have the meanings defined above) or a salt thereof and subjecting the compound of general formula (IV) thus obtained (wherein R, R?1, R2 and R3¿ are as stated above) to hydrolysis after or without isolation and if desired converting the compound of general formula (I) thus obtained into a salt thereof or setting free the same from its salt. The compounds of general formula (I) are known antibacterial agents. The advantage of the process of the present invention is that it makes the desired compounds of general formula (I) available in a simple manner, with high yields and in a short reaction time.</p> |
