| abstract |
A process for purifying benzoic acid, especially benzoic acid obtained by the catalytic oxidation of toluene in the liquid phase which can be contaminated with impurities such as diphenyl, methyldiphenyl, a phenyl-benzoic acid, benzaldehyde, benzyl benzoate, succinic anhydride, phthalic anhydride, formic acid or formaldehyde, by contacting the benzoic acid with an amine of the formula n n H.sub.2 N -- R n n wherein R is hydrogen, a straight or branched chain alkyl radical of 1 to 4 carbon atoms or a cycloalkyl radical of 5 or 6 carbon atoms or a salt thereof and benzoic acid is distilled off or sublimed from the resultant reaction mixture. The benzoic acid so obtained can be reacted with sodium hydroxide solution and highly pure sodium benzoate can be removed by extraction with toluene or steam distillation. |