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organic compounds
In the title compound, C8H9NO4, the hydrogen bonds between the oxime O atoms and the N and O atoms of the neighbouring asymmetric unit results in the dimerization of the molecules, with DA distances of 2.774 (3) and 3.144 (3) Å for O-HN and O-HO, respectively. The hydrogen-bridged centrosymmetric dimers are cross-linked via additional weaker intermolecular hydrogen bonds between the CH3 group and the other O atom of the dimer, forming a polymeric network. The DA distance of this second-order interaction (C-HO) is 3.450 (2) Å. Structure analysis indicates that the oxime is in an E configuration. The whole molecule is planar, with maximum deviation from the least-squares plane 0.104 (2) Å.