(2E)-2-[(2-Hydroxy-4-methoxyphenyl)(phenyl)methylidene]-N-phenylhydrazinecarboxamide dimethylformamide monosolvate

The title compound, C21H19N3O3·C3H7NO, adopts an E conformation with respect to the azomethine bond and crystallizes in the amide form. The dihedral angle between the rings lined to the C=N bond is 88.60 (12)°. The dimethylformamide solvent molecule is disordered over two orientations with site occupancies of 0.684 (3) and 0.316 (3). The two N atoms of the hydrazinecarboxamide group are involved in intermolecular N—H⋯O hydrogen bonds in which the dimethylformamide O atom acts as acceptor. The structure also features π–π interactions, with a centroid–centroid distance of 3.6561 (13) Å. Classical and non-classical intramolecular O—H⋯N and C—H⋯O hydrogen bonds are also present.

The title compound, C 21 H 19 N 3 O 3 ÁC 3 H 7 NO, adopts an E conformation with respect to the azomethine bond and crystallizes in the amide form. The dihedral angle between the rings lined to the C N bond is 88.60 (12) . The dimethylformamide solvent molecule is disordered over two orientations with site occupancies of 0.684 (3) and 0.316 (3). The two N atoms of the hydrazinecarboxamide group are involved in intermolecular N-HÁ Á ÁO hydrogen bonds in which the dimethylformamide O atom acts as acceptor. The structure also featuresinteractions, with a centroidcentroid distance of 3.6561 (13) Å . Classical and non-classical intramolecular O-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds are also present.   Table 1 Hydrogen-bond geometry (Å , ).   et al., 2007). The N1-N2 and N2-C8 bond distances of 1.364 (2) Å and 1.377 (2) Å respectively are greater than that for a double bond and less than that for a single bond which indicate appreciable delocalization of π-electron density over the semicarbazone chain (Reena & Kurup, 2010). Rings Cg1 ii (comprising atoms C1-C6) and Cg2 iii (comprising atoms C9 -C14) make a dihedral angle of 14.43 (12)° with each other while rings Cg1 ii and Cg3 iv (comprising atoms C15-C20) are twisted away from each other by a dihedral angle of 88.60 (12)° [symmetry codes: (ii)1 -x,1 -y,1 -z; (iii)1 + x,3/2y,1/2 + z; (iv)x,3/2 -y,1/2 + z]. The dimethylformamide solvent molecule is disordered with site occupancies of 0.684 (3) and 0.316 (3).  (Table 1). A prominent π···π interaction is observed with a centroid-centroid distance of 3.6561 (13) Å between the Cg1 ii rings of two molecules. Other short ring interactions are weak as they correspond to a distance greater than 4 Å. Two types of C-H···π interactions with H···π distances of 3.3114 and 3.3197 Å are also present in the crystal system.

Experimental
The title compound was prepared by adapting a reported procedure (Sreekanth et al., 2004). To a warm methanolic solution of N-phenylsemicarbazide (0.302 g, 2 mmol), a methanolic solution of 2-hydroxy-4-methoxybenzophenone (0.456 g, 2 mmol) was added and the resulting solution was refluxed for 2 h after adding a drop of conc. HCl. On cooling supplementary materials sup-2 . E68, o1519-o1520 the solution colorless crystals were separated out. Single crystals suitable for X-ray diffraction studies were obtained by slow evaporation of its solution in a 1:1 mixture of methanol and DMF.

Refinement
All H atoms on C were placed in calculated positions, guided by difference maps, with C-H bond distances 0.93-0.97 Å.
H atoms were assigned as U iso =1.2Ueq (1.5 for Me). N2-H2′, N3-H3′ and O1-H1 H atoms were located from difference maps and restrained using DFIX instructions. All the C, N and O atoms of the dimethylformamide molecule are disordered over two sites A and B with relative occupancies of 0.637 (4) and 0.363 (4) respectively..  The molecular structure of the title compound, showing the disordered DMF solvent molecule.

Figure 2
A view of the unit cell along c axis. 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.

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