Crystal structure of ethyl 2-[9-(5-bromo-2-hydroxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridin-10-yl]acetate

In the title compound, C23H24BrNO5, the central 1,4-dihydropyridine ring of the 1,2,3,4,5,6,7,8,9,10-decahydroacridine ring system adopts a half-chair conformation. The two cyclohexene rings fused to the central ring both have a twisted-boat conformation. The mean planes of the bromohydroxyphenyl ring and the major and minor components of the disordered ethyl aminoacetate moiety make dihedral angles of 78.99 (12), 85.9 (2) and 88.3 (9)°, respectively, with the 1,4-dihydropyridine ring. The terminal ethyl group of the ethyl aminoacetate moiety is disordered over two sets of sites with refined occupancies of 0.768 (17) and 0.232 (17). The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, forming an S(8) ring motif. In the crystal, C—H⋯O hydrogen bonds connect the molecules into layers parallel to (001), enclosing R 1 2(7) ring motifs.

All bond lengths and bond angles in the title molecule are within the normal ranges and comparable with each other and with those obtained earlier for similar compounds.
The molecular conformation is stabilized by an intramolecular O-H···O hydrogen bond, which generates an S(8) ring motif ( Fig. 1, Table 1).

S2. Experimental
A mixture of 1 mmol (112 mg) of cyclohexane-1,3-dione, 1 mmol (201 mg) of 4-bromo-2-hydroxybenzaldehyde and 1 mmol (103 mg) ethyl 2-aminoacetate in 30 ml ethanol was refluxed at 351 K. The reaction was monitored by TLC until completion. The solid product was deposited on cooling and collected by filtration under vacuum. Recystallization of the crude product from ethanol afforded crystals sufficient for X-ray diffraction. M.p. 515 K.

S3. Refinement
The hydroxyl hydrogen atom was found from a difference Fourier map and its O-H bond length was restrained using a

Figure 1
View of the title molecule with displacement ellipsoids drawn at the 30% probability level. Only the major component

Figure 2
The packing of molecules in the the title compound viewed down [100]. Hydrogen bonds are shown as dashed lines.
Hydrogen atoms not involved in hydrogen bonding and the minor component of disorder have been removed for clarity.  Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.