(2E)-2-[1-(2-Hydroxy-4-methoxyphenyl)ethylidene]-N-phenylhydrazinecarboxamide monohydrate

The title compound, C16H17N3O3·H2O, exists in the E conformation with respect to the azomethine C=N double bond. While the phenyl ring is almost coplanar with the central hydrazinecarboxamide group [dihedral angle = 14.18 (11)°], it is twisted slightly with respect to the other aromatic ring in the molecule, with a dihedral angle of 22.88 (13)°. The packing is dominated by O—H⋯O, N—H⋯O and C—H⋯O hydrogen-bond interactions, forming a three-dimensional supramolecular structure which is augmented by two types of C—H⋯π interactions. An intramolecular O—H⋯N interaction is also present in the molecule.

The title compound, C 16 H 17 N 3 O 3 ÁH 2 O, exists in the E conformation with respect to the azomethine C N double bond. While the phenyl ring is almost coplanar with the central hydrazinecarboxamide group [dihedral angle = 14.18 (11) ], it is twisted slightly with respect to the other aromatic ring in the molecule, with a dihedral angle of 22.88 (13) . The packing is dominated by O-HÁ Á ÁO, N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen-bond interactions, forming a three-dimensional supramolecular structure which is augmented by two types of C-HÁ Á Á interactions. An intramolecular O-HÁ Á ÁN interaction is also present in the molecule.
The compound crystallizes in monoclinic space group P2 1 /c. The molecule adopts an E configuration with respect to C7═N1 bond (Sithambaresan & Kurup, 2011;Siji et al., 2010) and it exists in amido form with C9═O3 bond length of 1.212 (3) Å which is very close to a formal C═O bond length [1.21 Å] (Allen et al., 1987). The phenyl ring is almost coplanar with the central hydrazinecarboxamide moiety with maximum deviation of -0.060 (3) (Table 1) links the adjacent molecules directly and through water molecule forming an infinite three-dimensional supramolecular structure in the lattice (Fig. 2). Phenylhydrazinecarboxamide molecules also interact through two types of C-H···π interactions ( Fig. 3) with the H···π distances of 2.92 and 2.79 Å and very weak π-π interactions with a shortest centroid-centroid distance of 5.0552 (18) Å. The parallel arrangement of the molecules along b axis is shown in Fig. 4.

Experimental
The title compound was prepared by adapting a reported procedure (Sreekanth et al., 2004). To a warm ethanolic solution of N-phenylsemicarbazide (0.302 g, 2 mmol), an ethanolic solution of 1-(2-hydroxy-4-methoxyphenyl)ethanone (0.332 g, 2 mmol) was added and the resulting solution was refluxed for 3 h after adding three drops of glacial acetic acid. On cooling the solution colorless crystals were separated out. Single crystals suitable for X-ray diffraction studies were obtained by slow evaporation from its ethanolic solution.

Refinement
All H atoms on C were placed in calculated positions, guided by difference maps, with C-H bond distances 0.93-0.96 Å. H atoms were assigned as U iso = 1.2Ueq. H1A and H1B atoms of O1S were located from difference maps and restrained using DFIX and DANG instructions with O-H = 0.86 (2) and H···H = 1.36 (2) Å respectively. N2-H2N, N3 -H3 and O2-H2′ atoms were located from difference maps and restrained using DFIX instructions with bond distance of 0.88 (1) Å.

Figure 1
ORTEP view of the compound, drawn with 50% probability displacement ellipsoids for the non-H atoms.

Figure 4
Packing diagram of the compound showing the parallel arrangement of the molecules along b axis.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq O1 0.00919 (