Abstract The rates of the reaction of 2, 4-dinitrophenylpyridinium chloride with ring-substituted anilines in methanol have been estimated by the gravimetry of the produced glutacondialdehyde dianil. The rates have been found to be second-order with aniline and first-order with pyridinium salt. The electron-withdrawal groups in pyridine accelerate the reaction. These facts suggest a mechanism involving a nucleophilic attack of the molecules of aniline on a complex consisting of 2 molecules of aniline and a pyridinium ion. The products of the reaction of 2, 4, 6-trinitrophenylpyridinium chloride with aniline were 2, 4, 6-trinitrodiphenylamine and the dianil.