(R)-2-Cyano-N-(1-phenylethyl)acetamide

In the title compound, C11H12N2O, the dihedral angle between the acetamide group and the benzene ring is 68.7 (1)°. In the crystal, N—H⋯O and weak C—H⋯O hydrogen bonds link the molecules into chains along the a-axis direction.

In the title compound, C 11 H 12 N 2 O, the dihedral angle between the acetamide group and the benzene ring is 68.7 (1) . In the crystal, N-HÁ Á ÁO and weak C-HÁ Á ÁO hydrogen bonds link the molecules into chains along the a-axis direction.

Gupta and Rajni Kant Comment
As part of our investigations on acetamide derivatives, the title compound has been prepared and its crystal structure is presented here.Bond lengths and angles in the title compound ( Fig. 1) are comparable with the similar crystal structures (Resende et al., 2003;Gálvez et al., 2010). The dihedral angle between the acetamide group (C2/C3/O1/N2) and the benzene ring (C6-C11) is 68.7 (1)°. N-H···O and weak C-H···O hydrogen bonds link the molecules into chains along the a axis ( Fig.2, Table 1). In the crystal, molecules are packed into layers parallel to the bc-plane (Fig.3).

Experimental
The reaction of methyl 2-cyanoacetate (0.1 g, 0.01 mol) and (R)-1-phenylethanamine (0.1 g, 0.01 mol) were carried out in the presence of dilute acetic acid and the reaction mixture was allowed to stir at room temperature for 6-7 h in dry dichloromethane (25 ml). The progress of the reaction was monitored by TLC. Upon completion, the solvent was removed under reduced pressure and residue was extracted with ethyl acetate. The compound was purified by successive recrystallization from methanol (yield 83%). The melting range was found to be 393-395 K.

Refinement
All H atoms were positioned geometrically and were treated as riding on their parent C/N atoms, with C-H distances of 0.93-0.98 Å and N-H distance of 0.86 with U iso (H) = 1.2U eq (C) or 1.5U eq (methyl C). The 799 Friedel equivalents were merged. The absolute configuration could not be established from the X-ray data, but was already known from the known configuration of the starting material.

(R)-2-Cyano-N-(1-phenylethyl)acetamide
Crystal data 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.