| 摘要 |
<p>This invention relates to an improved process for the preparation of quinolone drugs of the formula (I), wherein R=C1-C6 alkyl, C3-C6 cycloalklyl, aryl, substituted aryl, NR<1>R<2>=diarylamino, arylalkylamino, C1-C6-dialkylamino, piprazinyl, N or C alkyl (C1-C6) substituted piperazinyl, morpholino, pyrrolidinyl, substituted pyrrolidinyl, aralkyl, substituted aralkyl etc. Some of the compounds falling within the formula (I) are ciprofloxacin, enrofloxin, pefloxacin, etc. These compounds are useful as antibacterial drugs. The process of the present invention for preparation of compound of formula (I) comprises in enhancing the reactivity of the displaceable halogen (X) in the compound of the formula (II) towards various amines of formula (III) wherein R=as defined for compound of formula (I), R<3>=COOR<6 >(R<6>=C1-C6 alkyl, aryl, aralkyl), nitrile a carboxamide (-CONR<7>R<8>, R<7 >and R<8>=C1-C6 alkyl, C3-C6 cycloalkyl, aralkyl), X=Cl, Br, F; NR<1>R<2>=as defined above by introducing a nitro group ortho to the displaceable halo group and subsequently removing the nitro group in a conventional manner. The process of the present invention enhances the yield of the compound of the formula (I) and also improves the quality of the prepared compound.</p> |
