Molecules of the title compound, C(16)H(13)N(5)O(2), have no internal symmetry despite the symmetric pattern of substitution in the pyrimidine ring. The intramolecular distances indicate polarization of the electronic structure. There are two intramolecular N-H...O hydrogen bonds and molecules are linked into centrosymmetric dimers by pairs of three-centre C-H...(O)(2) hydrogen bonds. These dimers are linked into chains by means of a pi-pi stacking interaction.