Production methods of alpha, alpha, alpha-trifluoromethylphenyl-substituted benzoic acid and intermediate therefor

The present invention relates to a production method of compound [V] useful as an intermediate for medicaments and agrochemicals. The method includes reacting compound [III] with hexamethylenetetramine under heating to give compound [IV], and oxidizing the obtained compound [IV] with a halous acid salt or a ruthenium compound. According to the present invention, moreover, an organometallic compound having a tolyl group and compound [I] are cross-coupled in the presence of a catalyst to give compound [II] useful as an intermediate for medicaments and agrochemicals. The compound [II] is halogenated to give compound [III]. wherein X is halogen atom.