1-Chloromethylsulfinyl-2-nitrobenzene

In the title compound, C7H6ClNO3S, the nitro group forms a dihedral angle of 2.7 (4)° with the benzene ring. The bond-angle sum at the S atom is 303.7°. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds, forming layers lying parallel to (-101).

In the title compound, C 7 H 6 ClNO 3 S, the nitro group forms a dihedral angle of 2.7 (4) with the benzene ring. The bondangle sum at the S atom is 303.7 . In the crystal, molecules are linked by weak C-HÁ Á ÁO hydrogen bonds, forming layers lying parallel to (101).
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 1999).  The use of sulfoxides as pharmaceutical has shown promise in recent years (e.g. Melzig et al., 2009 andHuang et al. 2010). As part of our ongoing studies on the synthesis, structures and biological activity of organometallic sulfanilamide complexes we have synthesized and determined the crystal structure of the title compound (I). The molecular geometry and the atom-numbering scheme are shown in Fig 1. In the crystal structure of the title compound, there are two pairs of molecules enantiomers in the unit cell. In each molecule, the nitro group forms a dihedral angle of 2.7 (4)° with the phenyl ring very different to that found in 2-(methylsulfinyl)benzamide (25.6°) (Yan, 2010) and in benzamide (26.31°) (Kobayashi et al., 2003). The crystal packing is stabilized by weak C-H···O hydrogen bonds ( Fig. 2) forming noninteracting layers parallel to (-101) planes.

Experimental
O-chloronitrobenzene (1.60 g, 10 mmol) and thioacetic acid (0.80 g, 10 mmol) were dissolved in 75 ml aqua ethanol solution (25 ml water + 50 ml ethanol) and refluxed for 3 h under continuous stirring. Then the obtained product was evaporated at room temperature to dryness. The residue was diluted in 50 ml pure ethanol. After few days, orange bocks were recovered, as the solvent slowly evaporated.

Refinement
All non-H atoms were refined with anisotropic atomic displacement parameters. Approximate positions for all H atoms were first obtained from the difference electron density map. However, the H atoms were situated into idealized positions and the H-atoms have been refined within the riding atom approximation. The applied constraints were as follow: C aryl -H aryl = 0.95 Å and C methylene -H methylene = 0.99 Å. U iso (H aryl / methylene ) = 1.2U eq (C aryl /C methylene ).

Computing details
Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 1999   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 > σ(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.