The invention discloses a synthesis process for
sodium valproate. The synthesis process comprises the following steps: mutually dissolving
diethyl malonate and 1-bromopropane, slowly adding the obtained mixture into an
ethanol solution of
sodium ethoxide at a certain temperature, carrying out heating and
reflux for 2 h, recovering
ethanol until temperature is 110 DEG C, carrying out cooling to less than 80 DEG C, adding a certain amount of water to dissolve
sodium bromide, carrying out layering to obtain a plurality of
layers, then adding an
aqueous sodium hydroxide solution with a concentration of 15 to 30%, carrying out
hydrolysis at 60 to 70 DEG C for 3 h, then carrying out heating to recover
ethanol until a
gas phase temperature is 99 DEG C, carrying out cooling to less than 80 DEG C, adding
hydrochloric acid for
neutralization and acidifying, adding crude
valproic acid to dissolve dipropylmalonic acid so as to obtain mixed acid and subjecting the mixed acid to
slow heating and
decarboxylation at 110 to 160 DEG C for production of crude
valproic acid; and subjecting the crude
valproic acid to rectification and refining, adding a certain amount of the
aqueous sodium hydroxide solution for
neutralization, adding
toluene for
reflux to bring out water, thereby allowing sodium valproate to dehydrate and crystallize and then successively carrying out filtering, washing with
chloroform and
drying so as to obtain finished sodium valproate. The process is safe and environment-friendly, produces good-quality sodium valproate, has low cost and is suitable for industrial production.