Experimental

disorder in main residue; R factor = 0.050; wR factor = 0.147; data-to-parameter ratio = 26.6. In the title compound, C33H27BrClNO4, the dihydropyridine ring adopts a flattened boat conformation. The molecular conformation is stabilized by an intramolecular O—H O hydrogen bond, with an S(8) ring motif. In the crystal, O— H O, C—H O and C—H Cl hydrogen bonds, and C— H interactions link the molecules, forming a three-dimensional network. In the acridinedione ring system, the two ring C atoms at the 2- and 3-positions, and the C atom at the 6-position and the atoms of the phenyl ring attached to the C atom at the 6-position are disordered over two sets of sites with occupancy ratios of 0.783 (5):0.217 (5) and 0.526 (18):0.474 (18), respectively. Related literature For different industrial applications of acridine-1,8-diones, see: Murugan et al. (1998); Srividya et al. (1996, 1998). For various pharmaceutical properties of acridine-containing compounds, see: Girault et al. (2000); Sánchez et al. (2006)