The application belongs to the field of
medicine synthesis, and particularly discloses a preparation method of
benserazide hydrochloride. The
benserazide hydrochloride is prepared by the following steps: 2,3,4-trihydroxybenzaldehyde is used as a starting material to react with hydrazine
hydrate to obtain 2,3,4-trihydroxybenzylhydrazine, and then the 2,3,4-trihydroxybenzylhydrazine is subjected to esterolysis reaction with
serine methyl
ester hydrochloride to obtain the target product
benserazide hydrochloride. Compared with the method reported in the prior art, the method has the advantages of short reaction steps, simple
reaction conditions, less process impurities, good
quality control, simple raw materials, low large-scale production cost, and the like, and therefore the benserazide hydrochloride prepared by the method is good in application in a pharmaceutical composition.