2-{N-[(2,3,4,9-Tetrahydro-1H-carbazol-3-yl)methyl]methylsulfonamido}ethyl methanesulfonate

In the title compound, C17H24N2O5S2, the indole ring system is nearly planar [maximum deviation = 0.032 (1) Å] and the cyclohexene ring has a half-chair conformation. In the crystal, N—H⋯O hydrogen bonds link the molecules into a chain running along the b-axis direction. Weak C—H⋯O hydrogen bonds and weak C—H⋯π interactions are observed between the chains.

In the title compound, C 17 H 24 N 2 O 5 S 2 , the indole ring system is nearly planar [maximum deviation = 0.032 (1) Å ] and the cyclohexene ring has a half-chair conformation. In the crystal, N-HÁ Á ÁO hydrogen bonds link the molecules into a chain running along the b-axis direction. Weak C-HÁ Á ÁO hydrogen bonds and weak C-HÁ Á Á interactions are observed between the chains.

Related literature
For tetrahydrocarbazole systems present in the framework of a number of indole-type alkaloids of biological interest, see: Saxton (1983). For the antitumor activity of tetrahydrocarbazoles containing an amine unit, see: Chen et al. (2009). For the most potent drugs, such as ellipcitine and olivacine, for the treatment of a variety of cancers, see: Pelletier (1970).   Table 1 Hydrogen-bond geometry (Å , ).
Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009  Tetrahydrocarbazole systems are present in the framework of a number of indole-type alkaloids of biological interest (Saxton, 1983). The structures of tricyclic, tetracyclic and pentacyclic ring systems with dithiolane and other substituents of the tetrahydrocarbazole core, have been reported previously (Patır et al., 1997). Nitrogen containing heterocyclic compounds are encountered in a very large number of groups of organic compounds. They play a vital role in the metabolism of all living cells, which are widely distributed in nature and are essential to life. One of them pyridocarbazoles such as ellipcitine and olivacine are some of the most potent drugs for the treatment of a variety of cancers (Pelletier, 1970). Tetrahydrocarbazoles have been used as key compounds for the syntheses of various pyridocarbazoles (Knölker & Reddy, 2002). Amine moiety containing tetrahydrocarbazoles have also been showed antitumor activity (Chen et al., 2009). The present study was undertaken to ascertain the crystal structure of the title compound.
The molecule of the title compound contains a carbazole skeleton with methyl sulfonamide and ethyl methanesulfonate groups, (Fig. 1). In all structures atom N9 is substituted.
In the crystal, N-H···O hydrogen bonds (Table 1) link the molecules into a chain running along the b-axis direction ( Fig. 2), and weak C-H···O hydrogen bonds and a weak C-H···π interaction (Table 1) are observed between the chains.

Experimental
For the preparation of the title compound, (I), a solution of 2-((2,3,4,9 -tetrahydro-1H-carbazole-3-yl)methylamino)ethanol (1.0 g, 4.1 mmol) in pyridine (5 ml) was cooled to 273 K. Then, methanesulphonyl chloride (1.0 g, 9.0 mmol) was added dropwise. The mixture was stirred for 18 h at room temperature, and then washed with hydrochloric acid (10%). The organic layer was extracted with chloroform and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography eluting with ethyl acetate:hexane (1:1). The solvent was evaporated under reduced pressure and the residue was recrystallized from methanol (yield; 1.1 g, 67%, m.p. 404 K).

Refinement
H9 atom is located in a difference Fourier synthesis and refined isotropically. The remaining C-bound H-atoms were positioned geometrically with C-H = 0.95, 1.00, 0.99 and 0.98 Å, for aromatic, methine, methylene and methyl Hatoms, respectively, and constrained to ride on their parent atoms, with U iso (H) = k × U eq (C), where k = 1.5 for methyl Hatoms and k = 1.2 for all other H-atoms.

Figure 1
The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.  Special details 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.