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organic compounds
The reaction of ethyloxalyl chloride and naphthalene-1,8-diamine in refluxing tetrahydrofuran yielded the title compound, C18H18N2O6. The crystal structure analysis reveals a molecule with one oxamate substitutent nearly coplanar with the aromatic naphthalene system, while the second is strongly twisted with respect to the naphthalene system. Three strong intramolecular hydrogen bonds are observed, one in each oxamic acid ethyl ester group and one linking the two substitutents. Symmetry-related molecules are connected by a fourth intermolecular hydrogen bond.