Ethyl (Z)-2-chloro-2-[2-(4-methoxyphenyl)hydrazin-1-ylidene]acetate

The molecule of the title compound, C11H13ClN2O3, is planar (r.m.s. deviation = 0.0587 Å for non-H atoms) and adopts a Z conformation about the C=N double bond. In the crystal, molecules are linked via an N—H⋯O hydrogen bond, forming zigzag chains propagating along [010]. These chains are consolidated by C—H⋯O hydrogen bonds.

The molecule of the title compound, C 11 H 13 ClN 2 O 3 , is planar (r.m.s. deviation = 0.0587 Å for non-H atoms) and adopts a Z conformation about the C N double bond. In the crystal, molecules are linked via an N-HÁ Á ÁO hydrogen bond, forming zigzag chains propagating along [010]. These chains are consolidated by C-HÁ Á ÁO hydrogen bonds.
In the title compound, Fig. 1, the methoxy aromatic ring (C1-C6) is oriented at a dihedral angle of 3.05 (2) ° with respect to the mean plane of the ester moiety (N1/N2/C7-Cl1; planar to within 0.0 \%A). The molecule adopts a Z conformation around the C7═N2 double bond.
In the crystal, N-H···O and C-H···O hydrogen bonds connect the molecules to form zigzag chains along the b axis, enclosing six membered R 1 2 (6) ring motifs (Bernstein et al., 1995) -see Table 1 and Fig. 2.

Experimental
The molecule was synthesised according to the literature procedure (Asiri et al., 2011a) and recrystallized from ethanol giving yellow needle-like crystals.

Refinement
The NH H atom was located in a difference Fourier map and refined with U iso (H) = 1.2U eq (N). The C-bound H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.96 and 0.97 Å for CH(aromatic), CH 3 , and CH 2 H atoms, respectively, with U iso (H) = k × U eq (parent C-atom), where k = 1.5 for CH 3 H atoms and = 1.2 for other H atoms.

Figure 1
A view of the molecular structure of the title molecule with the atom numbering. The displacement ellipsoids are drawn at the 50% probability level.

Figure 2
A partial view along the a axis of the crystal packing of the title compound. The N-H···O and C-H···O hydrogen bonds are shown as dashed lines -see Table 1 for details.   (2) 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.