| abstract |
PURPOSE: To obtain the titled compound useful as a raw material of polyamide or polyimide and a hardener for epoxy resin, etc., suppressing the production of NO x , by oxidizing hydroxy-dicyclopentadiene with nitric acid while keeping the oxygen partial pressure in the reaction system within a specific range. n CONSTITUTION: 2,3,5-Tricarboxy-cyclopentylacetic acid is prepared by oxidizing hydroxy-dicyclopentadiene with nitric acid in the presence of a metallic salt catalyst such as ammonium metavanadate, sodium nitrite, etc., keeping the oxygen partial pressure in the reaction system to ≥0.5kg/cm 2 G (higher the better but preferably ≤50kg/cm 2 from the view point of safety). The reaction temperature is preferably 20W80°C, especially 40W60°C. By keeping the oxygen partial pressure within the above range, the generated NO is oxidized to nitric acid, the generation of NO x gas can be reduced remarkably, the concentration of nitric acid in the reaction liquid becomes high, and the yield of the objective compound by the crystallization and separation can be improved. n COPYRIGHT: (C)1984,JPO&Japio |