( <i>E</i> )-2,4-Diamino-5-{7-[(4-chlorophenyl)diazenyl]-3,3-dimethyl-1-oxo-2,3,4,9-tetrahydro-1 <i>H</i> -xanthen-9-yl}-6-oxo-1,6-dihydropyridine-3-carbonitrile dimethylformamide monosolvate

In the title compound, C₂₇H₂₃ClN₆O₃·C₃H₇NO, much of the mol-ecule is approximately planar, excluding the pyridinic ring, which is almost perpendicular to this plane, and the <i>sp</i> ³ atoms of the modified xanthene system. The diazene group is <i>E</i>-configured. In the extended structure, two hydrogen bonds of the type N-H⋯O and one N-H⋯Cl combine to form a layer structure parallel to (111). The solvent is severely disordered and this necessitated the use of SQUEEZE for a reliable refinement.