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organic compounds
In the title compound, C5H5N3O2, the amino H atom was localized in the vicinity of the endocyclic N atom at a distance of 0.94 (2) Å, showing that the compound exists in the form of a zwitterion. Bond lengths and molecular planarity [within 0.048 (1) Å] correspond to an overall -conjugated system. The molecules are coupled as centrosymmetric dimers through short Nendo-HNexo hydrogen bonds.