The title compound was synthesized by alkaline recyclization of isatin-7-carboxylic acid semicarbazone and used for the preparation of 3-oxo-2,3-dihydro-5H-1,2,4-triazino[5,6-b]indol-6-carboxylic acid (8) and 3-oxo-2,3,4,6-tetrahydro-1,2,4-triazino[5,6-c]cinnoline-7-carboxylic acid (9).