3-(4-Bromophenylsulfonyl)-8-methyl-1,3-diazaspiro[4.5]decane-2,4-dione

The crystal structure of the title compound, C15H17BrN2O4S, is stabilized by intermolecular N—H⋯O hydrogen bonds which link the molecules into centrosymmetric dimers. The dihedral angle subtended by the 4-bromophenyl group with the mean plane passing through the hydantoin unit is 83.29 (5)°. The cyclohexyl group adopts an ideal chair conformation with the methyl group in an equatorial position.

The crystal structure of the title compound, C 15 H 17 BrN 2 O 4 S, is stabilized by intermolecular N-HÁ Á ÁO hydrogen bonds which link the molecules into centrosymmetric dimers. The dihedral angle subtended by the 4-bromophenyl group with the mean plane passing through the hydantoin unit is 83.29 (5) . The cyclohexyl group adopts an ideal chair conformation with the methyl group in an equatorial position.

Comment
Diabetes is one of the major causes of disease related deaths in these modern times and the people in South-East Asia and Western Pacific are being the most at risk (Tiwari & Rao, 2002). To cure the disease sulfonyl ureas are the most frequently used antidiabetic drugs (DeFronzo, 1999;Feinglos & Bethel, 1998). An important complication related to this disease is the cataract formation and imidazolidine-2,4-diones have been found as aldose reductase inhibitors (Murakami et al., 1997).
The combination of the two scaffolds, i.e. the sulfonyl urea and the imidazolidine-2,4-dione, in one molecule may be a useful combination to cure the disease and associated complications, especially the cataract formation. With this hypothesis in mind, we synthesized a number of N-arylsulfonylimidazolidine-2,4-diones and evaluated their antidiabetic activity (Kashif & Ahmad et al., 2008) and their crystal structures (Hussain et al., 2009a;Hussain et al., 2009b;Kashif & Hussain et al., 2008). In this article, we report the synthesis and crystal structure of the title compound.
The structure of the title compound is presented in Fig. 1. The bond lengths and angles within the hydantoin (2,4-imidazolidenedione) moiety are normal, typical of those observed in cyclohexanespiro-5'-hydantoin (Gauthier et al., 1997;Kashif, Hussain et al., 2008). The hydantoin unit is planar (r.m.s. deviation of 0.007 Å). The cyclohexane ring adopts an ideal chair conformation with the methyl group in an equatorial position. The endocyclic torsion angles range from 55.2 (2) to 56.4 (2)°. The C1-O3 and C3-O4 bond lengths are 1.199 (2) and 1.226 (2) Å, respectively, which are close to the standard value for C═O (1.20 Å). The dihedral angle subtended by the p-bromophenyl group with the plane passing through the hydantoin moiety is 83.29 (5)°. Intermolecular N-H···O hydrogen bonds link the molecules to centrosymmetric dimers (Table 1).

Experimental
Substituted cyclohexanone (0.1 mol) and ammonium carbonate (0.6 mol) were placed in a 100 ml round bottom flask.
Potassium cyanide (0.1 mol) was dissolved in aqueous ethanol (60%) and added to the reaction flask. The mixture was heated on an oil bath at 328-333 K until the reaction was complete (monitored by TLC). After cooling to room temperature, the reaction mixture was concentrated and acidified using conc. HCl. The resulting precipitates were filtered, dissolved in saturated NaOH (aq) solution and extracted with diethyl ether (2 × 25 ml). The aqueous layer was acidified to precipitate 8-substituted-1,3-diazaspiro[4.5]decane-2,4-dione, which was filtered and recrystallized from ethanol/water. 8-substituted-1,3-diazaspiro[4.5]decane-2,4-dione (4.8 mmol) in CH 2 Cl 2 (20 ml) was stirred with triethylamine (4.8 mmol) and catalytic amounts of dimethylaminopyridine (DMAP). The 4-bromobenzene sulfonyl chloride (5.8 mmol) in CH 2 Cl 2 (10 ml) was added drop wise and the reaction mixture stirred at room temperature. After completion of the reaction (TLC), the mixture was diluted with 1 M HCl (20 ml) and extracted with CH 2 Cl 2 (3 × 25 ml). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Recrystallization of the residue from ethyl acetate afforded the colourless plate-like crystals, suitable for X-ray analysis.
supplementary materials sup-2 Refinement H atom on the N atom was refined isotropically. Other H atoms were placed in idealized positions and treated as riding atoms with C-H distance in the range 0.95-1.00 Å and U iso (H) = 1.2U eq (C) or 1.5U eq (C methyl ). Fig. 1. Molecular structure of the title compound with displacement ellipsoids at the 50% probability level showing atom-labelling scheme.