Synthetic method of lifitegrast

The invention provides a synthetic method of lifitegrast. The synthetic method of the lifitegrast is simple and short in synthetic route, and compared with the prior art, the method omits reaction steps such as protection and deprotection on functional groups, and only introduces a chiral structure in the last step, so that the configuration is kept unchanged in the reaction, and the racemizationrisk of chiral carbon atoms in the reaction process is reduced; reaction conditions are mild, few solvent types and side reactions are used, and heavy metals such as palladium are not used as catalysts in the synthesis process, so that the method is environment-friendly, and the cost is reduced; meanwhile, the total yield of the whole reaction route is high, and large-scale industrial production is facilitated. 本发明提供了一种利非司特的合成方法。本发明利非司特合成方法合成路线简短，与现有技术相比减少了官能团上保护和脱保护等反应步骤，且只在最后一步引入手性结构，反应中构型保持不变，减少了手性碳原子在反应过程中消旋风险；反应条件温和，使用溶剂种类及副反应较少，且在合成过程中不使用钯等重金属作为催化剂，既绿色环保，又降低成本；同时，整个反应路线总收率高，有利于大规模工业生产。