Patent ID: 7271285

Claim:
A process for producing an aromatic carboxylic acid, comprising the step of reacting an aromatic compound (C) represented by the following formula (1) Ar—H (1), wherein Ar is an aromatic cyclic group, with carbon monoxide (D) and molecular oxygen (E) in the presence of a palladium compound catalyst (A) and a catalyst (B) to thereby yield an aromatic carboxylic acid corresponding to the aromatic compound (C) except with one or more carboxyl groups bonded to its aromatic ring, the catalyst (B) comprising: a heteropolyacid or a salt thereof (B 1 ); and/or a mixture of oxo acids and/or salts thereof (B 2 ), the mixture (B 2 ) containing, as a whole, one of P and Si and at least one selected from the group consisting of V, Mo and W.