3-(5-Nitro-2-furyl)-1-phenylprop-2-yn-1-one

In the title compound, C13H7NO4, the 2-furyl ring is essentially planar, with a maximum deviation of 0.004 (1) Å. It is inclined at an angle of 11.69 (4)° to the benzene ring. The nitro group is slightly twisted out of the plane of the 2-furyl ring, with a dihedral angle of 5.72 (8)°. There is a short O⋯C contact of 2.8562 (8) Å (symmetry code: −x, −y, 2 − z). In the crystal packing, molecules are linked via a pair of intermolecular C—H⋯O hydrogen bonds, giving rise to an R 2 2(10) ring motif. Molecules are further linked into two-dimensional networks parallel to [100] via other intermolecular C—H⋯O hydrogen bonds. The crystal structure is consolidated by C—H⋯π interactions.

For general background to the biological activity of nitrofurans, see: Holla et al. (1986Holla et al. ( , 1987Holla et al. ( , 1992. For the preparation of the title compound, see: Rai et al. (2008). For bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 Table 1 Hydrogen-bond geometry (Å , ).
There is a short O4···C1 contact (symmetry code : -x, -y, 2 -z) with distance = 2.8562 (8) Å which is shorter than the sum of van der Waals radii of the O and C atoms. Bond lengths (Allen et al., 1987) and angles are within normal ranges.
The resulting mass of triethylamine hydrobromide was removed by filtration and the filtrate was concentrated by distilling the benzene under reduced pressure. The concentrated solution was cooled to room temperature. The product formed was collected by filtration and washed with ethanol. It was then recrystallized from ethanol. Crystals suitable for X-ray analysis were obtained from 1:2 mixtures of DMF and ethanol by slow evaporation.

Refinement
All H atoms were positioned geometrically and refined using a riding model with C-H = 0.93 Å and U iso (H) = 1.2U eq (C).
The highest residual electron density peak is located at 0.70 Å from C13 and the deepest hole is located at 1.10 Å from C1. Fig. 1. The molecular structure of the title compound showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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.