7-Nitro-5H-1-benzothiopyrano[2,3-b]pyridin-5-one

In the molecule of the title compound, C12H6N2O3S, the central heterocyclic ring is oriented at dihedral angles of 3.25 (6) and 2.28 (7)° with respect to the benzene and pyridine rings, respectively. The dihedral angle between the benzene and pyridine rings is 5.53 (7)°. In the crystal structure, intermolecular C—H...O hydrogen bonds link the molecules into chains.