Refinement manner of the val professional Acid which

摘要

PURPOSE: To provide a purification process capable of easily separating impurities from valproic acid in the production of valproic acid. ;CONSTITUTION: This purification process for valproic acid comprises the contact of an aqueous solution of a valproic acid salt containing a metal salt or ammonium salt of 2-allylvaleric acid and/or 2,2-diallylacetic acid with air or oxygen in the presence of sulfite ion or bisulfite ion and the separation of the metal salt or ammonium salt of 2-allylvaleric acid and/or 2,2-diallylacetic acid from the system in the form of a sulfonic acid salt adduct of the salt.;COPYRIGHT: (C)1996,JPO