Study On Synthesis Of Key Intermediate Of Moxifloxacin

Moxifloxacin is fourth-generation fluoroquinolone drug withbroad-spectrum antibacterial activities, good pharmacokinetics property,lower drug resistance, and high security. As a good antibacterial drug,moxifloxacin will have very broad application prospect，and huge marketpotential.（S, S）-2,8-diazabicyclo[4.3.0]nonan is the7-branched-chain ofmoxifloxacin，and it is also the key intermediate for synthesis ofmoxifloxacin. This paper importantly researched synthesis of the keyintermediate, the details of each reaction were as follows:（1） N-benzyl-2,3-dicarboxylicimide was synthesized by2,3-Pyridinedicarboxylic acid and benzylamine with methylbenzene as asolvent in the yield of87.4%.（2） Using Pd/C as a catalyst,8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane was prepared through hydrogenation reduction ofN-benzyl-2,3-dicarboxylicimide. The yield reached93.1%.（3）Use D-（–）-tartaric acid as resolution agent,（1S,6R）-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane was prepared from8-benzyl-7, 9-dioxo-2,8–diazabicyclo[4.3.0]nonane. The yield reached85.2%.（4） Using NaBH₄and BF3Et2O as a reductive agent,（S, S）-8-benzyl-2,8-diazabicyclo[4.3.0]nonane was prepared from （1S,6R）-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane in the yield of83.1%.（5）（S, S）-2,8-diazabicyclo[4.3.0]nonane was prepared throughhydrogenation reduction of （S, S）-8-benzyl-2,8-diazabicyclo[4.3.0]nonane with the yield of89.9%.we succeed in getting an industrial process route characterized byhigh yield, cheap and easily gained material，convenient operate and lowcost. The overall yield reached51.8%.