Oxidation of phenazine gave 2, 3-quinoxalinedicarboxylic acid in the yield of 70%, together with small amount of another acidic substance. The latter was obtained by the similar oxidation of 1-and 2-methoxyphenazine in the yields of 45% and 24%, respectively. From quinoxalinedicarboxylic acid, 2-quinoxaline-carbonamide, -carbohydrazide, and -hydroxamic acid were prepared and their antitubercular activities tested.
