(E)-Methyl N′-[1-(4-methoxyphenyl)ethylidene]hydrazinecarboxylate

The molecule of the title compound, C11H14N2O3, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxylate plane is 12.06 (9)°. Molecules are linked into a one-dimensional network by N—H⋯O hydrogen bonds and C—H⋯π interactions. The benzene rings of inversion-related molecules are stacked with their centroids separated by 3.777 (1) Å, indicating π–π interactions.

The molecule of the title compound, C 11 H 14 N 2 O 3 , adopts a trans configuration with respect to the C N bond. The dihedral angle between the benzene ring and the hydrazinecarboxylate plane is 12.06 (9) . Molecules are linked into a one-dimensional network by N-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions. The benzene rings of inversion-related molecules are stacked with their centroids separated by 3.777 (1) Å , indicatinginteractions.

Comment
Benzaldehydehydrazone derivatives have received considerable attention for a long time due to their pharmacological activity (Parashar et al., 1988) and their photochromic properties (Hadjoudis et al., 1987). Meanwhile, it's an important intermidiate of 1,3,4-oxadiazoles, which have been reported to be versatile compounds with many interesting properties (Borg et al., 1999). As a further investigation of this type of derivatives, the crystal structure of the title compound, C 11 H 14 N 2 O 3 ( Fig.1), is described here.
The title molecule ( Fig.1) adopts a trans configuration with respect to the C═N bond. The N1/N2/O2/O3/C10/C11 plane of the hydrazine carboxylic acid methyl ester group is slightly twisted away from the attached ring. The dihedral angle between the C2-C7 ring and the N1/N2/O2/O3/C10/C11 plane is 12.06 (9)°. The bond lengths and angles agree with those (Shang et al., 2007).
The molecules are linked into a one-dimensional network by N-H···O hydrogen bonds and C-H···π interactions (Table   1, Fig.2). The benzene rings of the inversion-related molecules are stacked with their centroids separated by a distance of 3.777 (1) Å, indicating π-π interactions.
Experimental 4-Methoxy-acetophenone (1.50 g, 0.01 mol) and methyl hydrazinecarboxylate (0.90 g, 0.01 mol) were dissolved in stirred methanol (15 ml) and left for 3.5 h at room temperature. The resulting solid was filtered off and recrystallized from ethanol to give the title compound in 80% yield. Crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution at room temperature (m.p. 470-472 K).

Refinement
The H atoms attached N2 were located in a difference map and its position and Uiso values were freely refined. C-bound H atoms were positioned geometrically (C-H = 0.93 or 0.96 Å) and refined using a riding model, with U iso (H) = 1.2 or 1.5U eq (C).

Special details
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.  (7) 0.0144 (7) 0.0075 (7) Geometric parameters (Å, °)