Process for the preparation of an aromatic carboxylic acid

Preparation of an aromatic carboxylic acid compound (I) comprises oxidation of alkyl aromatic compound, preferably isopropyl-substituted alkyl aromatic compound with nitric acid. Preparation of an aromatic carboxylic acid compound of formula (I) comprises oxidation of alkyl aromatic compound, preferably isopropyl-substituted alkyl aromatic compound with nitric acid. Either X : a phenyl group; and Y1H; or XY1+benzene ring A : a naphthalene ring; and n : 1-4. Where the carboxyl groups or other groups are located in any desired position on the two benzene rings or on the naphthalene ring. Independent claims are included for: (1) a preparation of 2,6-naphthalene dicarboxylic acid/4,4'-biphenyldicarboxylic acid comprising mixing 2,6-diisopropylnapthalene/4,4'-diisopropyl compound with an aqueous nitric acid (5 wt.%), and heating the reaction mixture at 140[deg]C; and (2) use of nitric acid for the oxidation of alkyl aromatic compound of formula (II) (where R is isopropyl group) to a corresponding aromatic carboxylic acid. [Image] [Image].