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organic compounds
The title compound, C7H4N4O4, was obtained by nitration of 5-nitro-1H-indazole. It has a planar indazole ring, with the N1-bound nitro group almost coplanar with the ring [twist angle 3.9 (2)°], while the C5-bound nitro group is twisted by 19.2 (2)° out of the plane of the molecule. The molecules in the crystal structure are arranged in planes. They are connected to each other by weak C—HO hydrogen bonds, with CO distances of 3.276 (3) Å.