The target product, tofisopam, is synthesized from com. available isoeugenenyl Me ether via two-step process with overall yield of 48%.The two-step process contains the steps of (1) polymerization and oxidation of isoeugenenyl Me ether to give 3-[2-(3,4-dimethoxybenzoyl)-4,5-dimethoxyphenyl]-5-pentanone and (2) cyclization of 3-[2-(3,4-dimethoxybenzoyl)-4,5-dimethoxyphenyl]-5-pentanone with hydrazine hydrate to give 1-(3,4-dimethoxyphenyl)-5-ethyl-7,8-dimethoxy-4-methyl-5H-2,3-benzodiazepine that was tofisopam.The intermediate and the target product are characterized by 1H NMR, 13C NMR and ESI-MS.The synthesis process has advantages of easily obtained raw materials, mild reaction conditions, easy control and high yield, and is suitable for large-scale production