Crystal structure of (6-bromo-2-oxo-2H-chromen-4-yl)methyl morpholine-4-carbodithioate

In the title compound, C15H14BrNO3S2, the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.034 (2) Å, and the morpholine ring adopts a chair conformation. The dihedral angle between best plane through the 2H-chromene ring system and the morpholine ring is 86.32 (9)°. Intramolecular C—H⋯S hydrogen bonds are observed. In the crystal, inversion-related C—H⋯S and C—H⋯O interactions generate R 2 2(10) and R 2 2(8) rings patterns, respectively. In addition, the crystal packing features π–π interactions between fused benzene rings [centroid–centroid distance = 3.7558 (12) Å].


S1. Comment
In recent years, much attention has been directed towards the synthesis of substituted coumarins owing to their tremendous application in various research fields including biological science and medicinal chemistry. Substituted coumarin derivatives are components of numerous natural products like warfarin, phenprocoumon, coumatetralyl, carbochromen, bromadialone, etc. These compounds also exhibit a wide band of biological activities including antibacterial, anti-HIV (Hesse & Kirsch, 2002), antiviral (Lee et al., 1998), anticoagulant (Jung et al., 2001), antioxidant (Melagraki et al., 2009) and anticancer activities (Jung et al.,(2004). Carbon-sulfur bond formation is a fundamental approach to bring sulfur into organic compounds, and this has received much attention due to its occurrence in many molecules that are of biological and pharmaceutical importance. The antibacterial and antifungal activities of dithiocarbamates were reported to arise by the reaction with HS-groups of the physiologically important enzymes by transferring the alkyl group of the dithioester to the HS-function of the enzyme (Schönenberger & Lippert, 1972).
Organic dithiocarbamates, ubiquitously found in a variety of biologically active molecules (Dhooghe & De Kimpe, 2006), are of high importance in academia as well as in industry.
In view of the various physiological activities of coumarins and dithiocarbamates, our current studies are focused on the development of new routes for the synthesis of coumarins incorporating dithiocarbamate moieties.

S2. Experimental
All the chemicals used were of analytical reagent grade and were used directly without further purification. The title compound was synthesized according to the reported method (Devarajegowda et al., 2013). The compound is recrystallized by ethanol-chloroform mixture. Colourless needles of the title compound were grown from a mixed solution of Ethanol/Chloroform (V/V = 2/1) by slow evaporation at room temperature. Yield =72%, m.p.: 433-435 K

S3. Refinement
All H atoms were positioned geometrically, with C-H = 0.93 Å for aromatic H and C-H = 0.97 Å for methylene H and refined using a riding model with U iso (H) = 1.2U eq (C) for aromatic and methylene H. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius.

Figure 2
Crystal packing for the title compound with hydrogen bonds drawn as dashed lines.