7-Chloro-4-phenethyl-2H-1,4-benzoxazin-3(4H)-one

In the crystal structure of title compound, C16H14ClNO2, the dihedral angle between the aromatic rings is 4.2 (2)°.


Related literature
As part of our continuing project on the study of the interactions occurring between small molecules and proteins (Li et al., 2008;Zuo et al., 2008), we report here the synthesis and crystal structure of the title compound. In the crystal structure, the two ring systems are nearly coplanar, the diehderal angle between the aromatic rings being 4.2 (2)°.

S2. Experimental
To the solution of 2-(2,4-dichlorophenoxy)-N-phenethylacetamide (0.684 g, 2.0 mmol) in DMF (20 ml), caesium carbonate (0.787 g, 2.4 mmol) was added. The mixture was refluxed for 1.5 h. After completion of the reaction (by TLC monitoring), the DMF was removed under vacuum. Water (20 ml) was added into the residue to obtain a turbid solution and it was extracted by ethyl acetate (20 ml x 4). The combined organic layers were washed three times with 10 mL of 1 mol/L hydrochloric acid and saturated sodium chloride solution (10 ml x 3), dried over MgSO 4 . And then the mixture was filtered and the filtrate obtained was concentrated under reduced pressure to obtain the corresponding crude product. The product was purified by column chromatography on silica gel using ethyl/acetate = 1/5 as eluent (yield 75%). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a solutionof the solid dissolved in ethyl acetate/hexane at room temperature for 10 days.

S3. Refinement
All H atoms were palced in calculated positions and refined as riding, with C-H = 0.93-0.97\%A, and with U iso (H)=1.2Ueq(C). The absolute structure was determined on the basis of 797Friedel pairs. supporting information

Figure 1
The molecular structure of the title compound with labelling and displacement ellipsoids drawn at the 50% probability level.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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.The absolute structure was determined on the basis of 800 Friedel pairs.

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