Abstract N-(α-Ketoacyl) anthranilic acids were prepared by oxidative ring opening of 3- hydroxyquinoline-2, 4 (1H, 3H)-diones by using paraperiodic acid (H 5 IO 6) or sodium periodate (NaIO 4). The optimisation of the reaction conditions is described as well as the utilisation of N-(α-ketoacyl) anthranilic acids in the preparation of anthranilic acid hydrochlorides.