4-(5-Chloropentanamido)benzenesulfonamide

The molecular conformation of the title compound, C11H15ClN2O3S, is stabilized by a C—H⋯O hydrogen bond, forming an S(6) ring motif. In the crystal, molecules are linked by two pairs of inversion-related N—H⋯O hydrogen bonds, generating R 2 2(8) and R 2 2(20) ring motifs, resulting in chains running along [0-11]. These chains are connected by N—H⋯O hydrogen bonds along [100], forming layers parallel to (011). There are also C—H⋯π interactions between the layers, which consolidate the three-dimensional structure.

The molecular conformation of the title compound, C 11 H 15 ClN 2 O 3 S, is stabilized by a C-HÁ Á ÁO hydrogen bond, forming an S(6) ring motif. In the crystal, molecules are linked by two pairs of inversion-related N-HÁ Á ÁO hydrogen bonds, generating R 2 2 (8) and R 2 2 (20) ring motifs, resulting in chains running along [011]. These chains are connected by N-HÁ Á ÁO hydrogen bonds along [100], forming layers parallel to (011). There are also C-HÁ Á Á interactions between the layers, which consolidate the three-dimensional structure.

4-(5-Chloropentanamido)benzenesulfonamide
Hasan Türkmen, Şerife Pınar Yalçın, Mehmet Akkurt and Mustafa Durgun Comment Sulfonamides represent an important class of biologically active compounds, with inhibitors of carbonic anhydrase enzyme, antibacterial properties in chemotherapy, antithyroid drugs, antimicrobial properties, (Maren, 1987;Rami et al., 2011;Supuran, 2008;Turkmen et al., 2005Turkmen et al., , 2011. Sulfonamides are also antiviral agents, such as as HIV protease inhibitors (De Clercq, 2001), and inhibitors of cysteine protease enzyme (Danial & Korsmeyer, 2004). The design and development of new sulfanilamide derivatives can help determine any structural requirements for improved biological activity. In this study, we have prepared and determined the crystal structure of the title compound.
A C-H···O hydrogen bond stabilizes the molecular conformation of the title molecule, forming a S(6) ring motif (Bernstein et al., 1995; Table 1). In the crystal, neighbouring molecules are linked by two pairs of intermolecular N-H···O hydrogen bonds (Table 1 & Fig. 2), forming inversion dimers with R 2 2 (8) and R 2 2 (20) ring motifs, into chains running along [0 -1 1]. These chains are connected by N-H···O hydrogen bonds along the [100] direction, forming layers parallel to the (011) plane. C-H···π interactions between these layers further help in stabilizing the supramolecular structure (Table 1).

Experimental
The title compound was prepared by a nucleophilic acyl substitution reaction of sulfanilamide with 5-chloropentano-

Refinement
The H atoms on the NH and NH 2 groups were located from a difference Fourier map and refined with distance restraints of N-H = 0.88 (1) Å, with U iso (H) = 1.2U eq (N). The C-bound H atoms were positioned geometrically, with C-H = 0.93 and 0.97 Å for CH and CH 2 H atoms, respectively, and refined as riding with U iso (H) = 1.2U eq (C).

Figure 1
The view of the molecular structure of the title molecule, with the atom numbering. Displacement ellipsoids are drawn at the 50% probability level.

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.