Crystal structure of 2-(1,3,7,9-tetra-methyl-2,4,6,8-tetra-oxo-1,2,3,4,6,7,8,9-octa-hydro-pyrido[2,3-d:6,5-d']dipyrimidin-5-yl)benzamide di-methyl-formamide hemisolvate.

The title compound, C20H18N6O5·0.5C3H7NO, crystallized as a di-methyl-formamide (DMF) solvate. In the main mol-ecule, the dihedral angle between the pyridodi-pyrimidine fused-ring system and the benzamide substituent is 82.26 (11)°. In the crystal, the benzamide mol-ecules are linked by N-H⋯O hydrogen bonds to generate tetra-mers with an approximate square-prismatic shape, which appears to correlate with the tetra-gonal crystal symmetry. The DMF mol-ecule is disordered about a crystallographic twofold axis and accepts a C-H⋯O inter-action from the benzamide mol-ecule.