METHOD OF ISOLATION AND PURIFICATION OF DICARBOXYLIC ACID FORMED UPON DIRECT OXIDATION OF CYCLIC C3-C20 HYDROCARBON Russian patent published in 2003 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: liquid- phase oxidation is carried out with molecular oxygen or oxygen-containing gas in solvent and in presence of catalyst dissolved in reaction medium. In case of appropriated reaction mixture, decantation of two liquid phases is effected: upper nonpolar phase with unreacted hydrocarbon and lower polar phase. Further, lower phase or, if necessary, all reaction mixture is distilled to give distillate and distillation residue including formed in reaction acids, catalyst, heavy compounds, at least part of solvent, and possibly intermediates and reaction by-products. Purification of distillation residue is performed by oxidation with molecular oxygen or with oxygen-containing gas, or with oxygen donors followed by distilling off solvent, intermediates and by-products possibly remained in mixture. Resulting carboxylic acid is recrystallized from water obtained in the oxidation stage, wherein carboxylic acid is formed. EFFECT: increased purity of product. 11 cl, 3 tbl, 2 ex