A two-step flow continuous synthesis process is developed for the synthesis of Edaravone from 1,3-dicarbonyl compounds or analogues and substituted hydrazine.The factors affecting the product quality and yield,such as reaction temperature,residence time,the dosages of solvent and cyclization alkali,are optimized.The optimal process conditions are determined for industrial continuous synthesis of Edaravone.It is found that compared with one-step intermittent method,the reaction time required by this two-step continuous method is shortened by nearly 93％,and the product yield is increased by 17％.Continuous process can effectively reduce the production cost and effectively avoid the product color being too dark due to the oxidation of raw materials exposed to air.High quality Edaravone can be obtained without needing purification,decolorization and recrystallization.
维普
万方数据