| abstract |
(57) [Summary] [Object] To provide a method for producing 1,2,3,4-butanetetracarboxylic acid in a high yield by incorporating an efficient method for separating and recovering a catalyst. [Structure] Containing a catalytic metal acid anion obtained by oxidizing tetrahydrophthalic anhydride or its hydrous acid using peroxidation in the presence of a catalyst consisting of tungstic acid, phosphotungstic acid or salts thereof, An aqueous solution of 2,3,4-butanetetracarboxylic acid is treated with a weakly basic anion exchange resin, and the exchange resin is subjected to an elution treatment with an alkali, and the obtained liquid is reused as a catalyst. |