In the title mol-ecule, C13H7N3O8, the phenyl and benzene rings are rotated from the mean plane of the central ester group by 18.41 (9) and 81.80 (5)°, respectively. The dihedral angle between the rings is 80.12 (14)°. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming helical chains along [010].