To obtain the subject compound of high purity with suppression of by-product formation by catalytic hydrogenation of 5-nitroisophthalic acid in the presence of a specific compound under specific conditions.
When 5-nitroisophthalic acid is catalystically hydrogenated to 5-aminoisophthalic acid in the presence of a catalyst, the hydrogenation reaction is carried out in the presence of an alkali metal hydroxide under the condition lower than the isoelectric point. In this reaction, the atmosphere of lower than the isoeletric point is preferably at a pH of 4-7 and the hydrogenation pressure is preferably set to ≤10 kg/cm2.G. Raney nickel and palladium on carbon catalyst is preferably used as a catalyst. 5-Aminoisophthalic acid is an important intermediate for production of a Roentgen contrast medium.
ASASHIGE NAOKI
NAKAMURA MITSUO
SEKI RYOICHI
Next Patent: PRODUCTION OF ISOCYANATE SHOWING LIGHT COLOR