4-Methyl-2-oxo-2H-chromen-7-yl 4-fluorobenzenesulfonate

In the asymmetric unit of the title compound, C16H11FO5S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.040 (2) Å. The dihedral angle between the 2H-chromene ring and the 4-fluorophenyl ring is 2.17 (8)°. One of the sulfonamide O atoms is approximately coplanar with the benzene ring [C—C—S—O torsion angle = 166.00 (14)°], whereas the other O atom lies well below the plane [C—C—S—O = −61.35 (17)°]. In the crystal, molecules are connected by weak C—H⋯O hydrogen bonds, forming two-dimensional networks parallel to the ac plane.

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  This work is to further explore the structural features of sulphur-containing small molecule derivatives which are being recently published from our laboratory (Sinha et al., 2011a,b;Al-Najjar et al., 2012). Recently, the O-SO 2 group have attracted attention in organic chemistry (Gu et al., 2007) and medicinal chemistry (Wrobel et al., 2002). Coumarines are also proven to be cytotoxic agents (Kostova, 2005). In this paper, we report the crystal structure of the title compound, which belongs to this class of compounds.
In the crystal, (Fig. 2), the molecules are connected via weak intermolecular C-H···O hydrogen bonds (Table 1) to form two-dimensional networks parallel to the ac plane.

Experimental
Detailed synthetic procedure has been described in Sinha et al. (2011a,b) and Fusegi et al. (2009).

Refinement
All hydrogen atoms were positioned geometrically [C-H = 0.95 or 0.98 Å] and were refined using a riding model, with U iso (H) = 1.2 or 1.5 U eq (C). A rotating group model was applied to the methyl groups.

Figure 2
The crystal packing of the title compound. Intermolecular hydrogen bonds are shown as dashed lines. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 1.14 e Å −3 Δρ min = −0.72 e Å −3 Special details Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K. Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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.