| abstract |
ABSTRACT OF THE DISCLOSURE A crude 11-cyano-undecanoic acid in the form of free acid or its ammonium salt is refined by bringing a refining gas containing ozone therein into contact with a solution of the crude 11-cyano-undecanoic acid or its ammonium salt in an organic solvent non-reactive with the ozone at a temperature of 0 to 100°C, for example, formic acid, acetic acid, propionic acid, chloroform, tetrachloromethane, dichlorethane and trichloroethane. |