Improvement Of The Synthesis Process Of Levofloxacin Mesylate

Levofloxacin mesylate is the third generation fluoroquinolone antibacterial drug,which has the advantages of broad spectrum,strong antibacterial activity,significant curative effect and small side effect,and is widely used in clinical practice.At present,the industrial production process is long,the product quality is poor and the production cost is high,which leads to the lack of market competitiveness of levofloxacin mesylate.The main purpose of this paper is to study a new synthetic process more suitable for industrial production and to provide the best process parameters for the industrial production of levofloxacin mesylate.In this paper,by studying the different reaction conditions(reaction temperature,reaction ratio,catalyst,etc.)the influence of the reaction,adopting qualitative judgment analysis method combined with quantitative analysis,developed a phase transfer catalyst(PTC)catalytic cyclization,hydrolysis,condensation "one-pot" mesylate levofloxacin synthesis of new technology.The improved process flow is: N,n-dimethylamine ethyl acrylate is chlorinated by(2,3,4,5)-tetrafluorobenzoyl chloride,replaced by(S)-(+)-2-aminopropanol,and synthesized by PTC/ potassium carbonate.Levofloxacin was obtained by condensation of levofloxacin with n-methylpiperazine in ammonia ethanol solution.Levofloxacin was added to mesylate to obtain levofloxacin mesylate.The results showed that the total impurities of the improved process products decreased from 0.5% to less than 0.2%,the yield increased from 53.6% to 69.5%,and the unit cost of raw materials decreased by 40 yuan.The reaction conditions of this process are mild,easy to operate,good reproducibility,energy saving and emission reduction are suitable for industrial production.