3-Butyl-5 , 5-diphenylimidazolidine-2 , 4-dione

Hydantoin is an important nucleus found in numerous natural products and in several clinically important medicines. One of the most significant hydantoin derivatives is 5,5diphenylimidazolidine-2,4-dione (phenytoin). As part of our ongoing studies of phenytoin derivatives (Ramli et al., 2017a,b; Akrad et al., 2017; Guerrab et al., 2017a,b), the title compound was prepared and its crystal structure is reported here. In the title molecule, Fig. 1, the imidazolidine-2,4-dione ring has phenyl groups attached to the 5-position. The C8–C13 and C14–C19 rings are inclined to the fivemembered ring by 58.08 (6) and 66.31 (5) , respectively. In the crystal, pairwise N2—H2 O2 hydrogen bonds (Table 1) form centrosymmetric dimers, which are connected into chains along the aaxis direction by pairwise C17— H17 N1 hydrogen bonds. The chains are then connected into thick layers approximately parallel to [010] by C18—H18 O1 hydrogen bonds (Table 1 and Fig. 2). The layers, in turn, are connected along the b-axis direction by C5—H5A Cg3 interactions (Table 2 and Figs. 3 and 4). Received 23 December 2017 Accepted 8 January 2018


Structure description
Hydantoin is an important nucleus found in numerous natural products and in several clinically important medicines. One of the most significant hydantoin derivatives is 5,5diphenylimidazolidine-2,4-dione (phenytoin). As part of our ongoing studies of phenytoin derivatives (Ramli et al., 2017a,b;Akrad et al., 2017;Guerrab et al., 2017a,b), the title compound was prepared and its crystal structure is reported here.

data reports Synthesis and crystallization
To a solution of 5,5-diphenylimidazolidine-2,4-dione (1 g), one equivalent of butyl bromide in absolute dimethylformamide (DMF) was added and the resulting solution heated under reflux for 3 h in the presence of 1.3 equivalents of K 2 CO 3. The reaction mixture was filtered while hot, and the solvent evaporated under reduced pressure. The residue obtained was dried and crystallized from an ethanol solution to yield colourless block-shaped crystals of the title compound (Guerrab et al., 2017c,d).

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.

Figure 2
Detail of the layer formation (plan view) viewed along the b-axis direction. N-HÁ Á ÁO, C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds are shown, respectively, as blue, black and pink dashed lines.

Figure 3
Elevation view of the layers seen along the c-axis direction. C-HÁ Á ÁN hydrogen bonds and C-HÁ Á Á(ring) interactions are shown, respectively, as pink and green dashed lines. Table 1 Hydrogen-bond geometry (Å , ).

Figure 1
The title molecule with labelling scheme and 50% probability ellipsoids.

Special details
Experimental. The diffraction data were obtained from 3 sets of 400 frames, each of width 0.5° in ω, colllected at φ = 0.00, 90.00 and 180.00° and 2 sets of 800 frames, each of width 0.45° in φ, collected at ω = -30.00 and 210.00°. The scan time was 15 sec/frame.

data-2
IUCrData (2018). 3, x180050 Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness 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 threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) 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.