2-[(3-Oxo-1-benzofuran-6-yl)oxy]acetonitrile

The molecule of the title compound, C11H8O3, is essentially planar [r.m.s. deviation = 0.025 (2) Å]. In the crystal, molecules are stacked along [110] but no short π–π contacts are observed. Weak C—H⋯O interactions link the molecules into chains along [101].


Related literature
127 parameters H-atom parameters constrained Á max = 0.18 e Å À3 Á min = À0.13 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). As a continuation of our progress in the development of hybrid drug candidates against tuberculosis, malaria and cancer (Morphy et al., 2004), the title compound was identified as a promising starting material. The compound was synthesized by reaction of 6-Hydroxy-benzofuran-3-one with propargyl bromide at comparatively low temperature in the presence of potassium carbonate (Hoogendoorn et al., 2011). To confirm the effect of temperature on the reaction, herein we report the single-crystal structure of the title Compound.
The molecular structure of the compound is shown in Figure 1. The molecule is essentially planar (r.m.s. deviation = 0.025 (2) Å). In the crystal the molecules are linked by infinite one-dimensional C-H···O hydrogen bonding into chains that propagate in the [101] direction (Table 1, Figure 2).

Experimental
A solution of 6-Hydroxy-benzofuran-3-one (1 g, 6.66 mm) in dry acetone was treated with potassium carbonate (1.3 g, 9.32 mm). The reaction mixture was heated at a temperature of 40 -50 °C for about 30 minutes and then propargyl bromide (1.6 ml, 14.65 mm) was added to it. The combined solution was stirred for about 2.5 h and concentrated under vacuum. The residue was diluted with water and extracted three times with ethyl acetate. The combined organic layer was washed with brine and water and dried over anhydrous magnesium sulfate. After that filtered and the filtrate solid product was recrystalized from ethyl acetate and hexane to afford 80% of the target compound as yellow crystal.

Refinement
All hydrogen atoms were positioned in geometrically idealized positions with C-H = 0.99 Å (methylene), 0.95 Å (aromatic and acetylenic). All hydrogen atoms were allowed to ride on their parent atoms with U iso (H) = 1.2U eq . The highest residual electron density of 0.18 e.Å -3 is 0.66 Å from C3.  Crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.18 e Å −3 Δρ min = −0.13 e Å −3 Special details Experimental. The intensity data was collected on a Bruker Apex DUO 4 K CCD diffractometer using an exposure time of 5 s/frame. A total of 2405 frames were collected with a frame width of 1° covering up to θ = 66.21° with 98.0% completeness accomplished. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq C1 0.33402 (7