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US 2004/0073030 A1Published application
Process for the preparation of quinolone derivatives
OwnerReddy Muddasani Pulla, Chowdary Nannapaneni Venkaiahinventors
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OwnerReddy Muddasani Pulla, Chowdary Nannapaneni Venkaiahinventors
Estimating the term…
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, NR1R2=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), R3=COOR6 (R6=C1-C6 alkyl, aryl, aralkyl), nitrile a carboxamide (—CONR7R8, R7 and R8=C1-C6 alkyl, C3-C6 cycloalkyl, aralkyl), X=Cl, Br, F; NR1R2=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. 1
Novel compound of the formula X
Novel compound of the formula VIII
Novel compound of the formula XII
Novel compound of the formula XIII
Novel compound of the formula XIV
Novel compound of the formula XV
An improved process for the preparation of compound of the general formula I as defined above which comprises
A process for the preparation of novel compound of the formula X
A process for the preparation of novel compound of the formula XII
A process for the preparation of novel compound of the formula XIII which comprises reacting the novel quinolone of the formula XII with an amine R1NHR2 (of the formula III) wherein R1 and R2 have the meanings given above.
A process for the preparation of novel compound of the formula XIV which comprises subjecting the compound of the formula XIII to metal reduction by conventional methods.
A process for the preparation of novel compound of the formula XV which comprises decomposing the compound of the formula XIV in the presence of copper (I) halide to give a halide derivative of the formula XV.
An improved process for the preparation of compound of the formula I as defined above substantially as herein described with reference to the Examples.
Dependencies are inferred from the claim text.