1,5-Bis(thiophen-2-yl)-3-(2,4,5-trimethoxyphenyl)pentane-1,5-dione

In the title 1,5-diketone compound, C22H22O5S2, the benzene ring makes dihedral angles of 41.51 (6) and 25.83 (6)° with the two thiophene rings, while the dihedral angle between the thiophene rings is 26.67 (7)°. An intramolecular C—H⋯O interaction generates an S(9) ring motif. In the crystal, molecules are linked into a three-dimensional network by weak C—H⋯O and C—H⋯π interactions, and a π–π interaction with a centroid–centroid distance of 3.6527 (8) Å.

In the title 1,5-diketone compound, C 22 H 22 O 5 S 2 , the benzene ring makes dihedral angles of 41.51 (6) and 25.83 (6) with the two thiophene rings, while the dihedral angle between the thiophene rings is 26.67 (7) . An intramolecular C-HÁ Á ÁO interaction generates an S(9) ring motif. In the crystal, molecules are linked into a three-dimensional network by weak C-HÁ Á ÁO and C-HÁ Á Á interactions, and ainteraction with a centroid-centroid distance of 3.6527 (8) Å .

Comment
Ketones are obviously one of the most important compounds in organic chemistry. There are many interesting applications of the compounds with the ketone group and the heterocyclic unit, which exhibit not only bioactivity such as antibacterial (Rai et al., 2008), anti-inflammatory (Pillai et al., 2004) and analgesic (Alagarsamy et al., 2007) activities, but also fluorescent property (Favaro et al., 2002). The 1,5-diketone compound is conventionally prepared by the oxidative cleavage of cyclopentenes or the conjugate addition of enolates to α,β-unsaturated ketones (Harrowven & Hannam, 1999).

Experimental
The title compound (I) is a symmetrical 1,5-diketone compound which was alternatively synthesized by the stirring of (E)-1-(2-thitenyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (0.57 g, 1.5 mmol) (Suwunwong et al., 2011) in methanol (15 ml) with a freshly prepared sodium methoxide (1.5 mmol of sodium in 40 ml of methanol). Excess malononitrile (0.20 g, 3.0 mmol) was then added with continuous stirring at room temperature until the precipitate separated out. The resulting solid was filtered. Colorless single crystals of the title compound suitable for X-ray structure determination was obtained by recrystalization from acetone/methanol (1:1 v/v) by the slow evaporation of the solvent at room temperature after several days.

sup-2 Figures
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.15320 (2