合成路线1

The reduction of 2,3,4-trichloro-5-fluoronitrobenzene (I) with Fe - HCl in hot water gives 2,3,4-trichloro-5-fluoroaniline (II), which by diazotation with NaNO2 - HCl and reaction with sodium tetrafluoroborate and cuprous cyanide is converted to 2,3,4-trichloro-5-fluorobenzonitrile (III). The reaction of (III) with KF in DMSO at 140 C affords 3-chloro-2,4,5-trifluorobenzonitrile (IV), which by hydrolysis with 30% HBr in refluxing acetic acid gives 3-chloro-2,4,5-trifluorobenzamide (V). The hydrolysis of (V) with 18N H2SO4 at 135 C yields the corresponding benzoic acid (VI), which is treated with refluxing SOCl2 to afford the acyl chloride (VII). The condensation of (VII) with diethyl malonate (VIII) by means of Mg - ethanol in hot toluene gives diethyl 3-chloro-2,4,5-trifluorobenzoylmalonate (IX), which is partially decarboxylated with p-toluenesulfonic acid in refluxing water to give ethyl 3-chloro-2,4,5-trifluorobenzoylacetate (X). The condensation of (X) with triethyl orthoformate (XI) in refluxing acetic anhydride yields ethyl 2-(3-chloro-2,4,5-trifluorobenzoyl)-3-ethoxyacrylate (XII), which is treated with cyclopropylamine (XIII) in ethanol to afford ethyl 2-(3-chloro-2,4,5-trifluorobenzoyl)-3-(cyclopropylamino)acrylate (XIV). The cyclization of (XIV) by means of NaF in DMF at 150 C gives ethyl 8-chloro-1-cyclopropyl-6,7-difluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate (XV), which is hydrolyzed with H2SO4 in refluxing water - acetic acid to the corresponding carboxylic acid (XVI). The condensation of (XVI) with 3-(tert-butoxycarbonylamino)pyrrolidine (XVII) by means of 1,8-diazabicyclo [5.4.0]undecane (DBU) in refluxing acetonitrile yields 7-[3-(tert-butoxycarbonylamino)-1-pyrrolidinyl]-8-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (XVIII), which is finally deprotected by a treatment with concentrated HCl in methanol.