N′-[(E)-5-Bromo-2-hy­droxy-3-meth­oxy­benzyl­idene]-4-meth­oxy­benzohydrazide monohydrate

P R Reshma; M Sithambaresan; M R Prathapachandra Kurup

doi:10.1107/S1600536812033806

. 2012 Sep 1;68(Pt 10):o2821–o2822. doi: 10.1107/S1600536812033806

N′-[(E)-5-Bromo-2-hydroxy-3-methoxybenzylidene]-4-methoxybenzohydrazide monohydrate

P R Reshma ^a, M Sithambaresan ^b,^*, M R Prathapachandra Kurup ^a

PMCID: PMC3470184 PMID: 23125628

Abstract

In the title compound, C₁₆H₁₅BrN₂O₄·H₂O, the hydrazide molecule is nearly planar, with a largest deviation from the mean plane through the non-H atoms of 0.106 (4) Å and a dihedral angle between the benzene rings of 1.98 (16)°. This molecule adopts an E conformation about the C=N bond and an intramolecular O—H⋯N hydrogen bond increases the rigidity. In the crystal, some molecules of the title hydrazide are replaced by molecules of its 6-bromo isomer, and the Br atom from this admixture molecule was refined to give a partial occupancy of 0.0523 (13). The hydrazide and water molecules are linked through classical N—H⋯O and O—H⋯O hydrogen bonds, forming layers parallel to (110). C—H⋯π interactions are also present.

Related literature

For the biological activity of hydrazone compounds, see: Metwally et al. (2006 ▶); Cukurovali et al. (2006 ▶). For the synthesis of related compounds, see: Emmanuel et al. (2011 ▶); Mangalam & Kurup (2011 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). For related structures, see: Tan (2012 ▶); Hou & Bi (2012 ▶); Shen et al. (2012 ▶).

Experimental

Crystal data

C₁₆H₁₅BrN₂O₄·H₂O
M _r = 397.22
Monoclinic,
a = 4.9730 (4) Å
b = 13.5721 (12) Å
c = 24.907 (2) Å
β = 90.921 (4)°
V = 1680.8 (2) Å³
Z = 4
Mo Kα radiation
μ = 2.47 mm⁻¹
T = 296 K
0.40 × 0.30 × 0.25 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.414, T _max = 0.539
12692 measured reflections
2939 independent reflections
2268 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.094
S = 1.06
2939 reflections
247 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.52 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2010 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812033806/yk2067sup1.cif

e-68-o2821-sup1.cif^{(19.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812033806/yk2067Isup2.hkl

e-68-o2821-Isup2.hkl^{(144.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812033806/yk2067Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg2 is the centroid of the C9–C14 benzene ring

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H21⋯O1W ⁱ	0.86 (1)	1.96 (2)	2.820 (4)	174 (3)
O2—H2⋯N1	0.87 (3)	1.83 (3)	2.595 (3)	146 (5)
O1W—H1W⋯O2	0.85 (3)	2.23 (3)	2.974 (4)	147 (4)
O1W—H2W⋯O3ⁱⁱ	0.86 (3)	1.82 (3)	2.675 (3)	177 (4)
C16—H16C⋯Cg2ⁱⁱⁱ	0.96	2.70	3.517 (3)	144

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

The authors are grateful to the Sophisticated Analytical Instruments Facility, Cochin University of Science and Technology, Kochi-22, India, for providing the single-crystal X-ray diffraction data. PRR thanks the Council of Scientific and Industrial Research, New Delhi, India, for a Junior Research Fellowship.

supplementary crystallographic information

Comment

Aroylhydrazones derived from the condensation reactions of aroylhydrazides with aldehydes show excellent biological properties (Cukurovali et al., 2006; Metwally et al., 2006). As an extention of the work on the structures of hydrazone derivatives (Tan, 2012; Hou & Bi, 2012; Shen et al., 2012), we report here the crystal structure of a new aroylhydrazone compound. The molecular structure of the title compound is shown in Fig. 1.

The molecule adopts an E conformation about the C7═N1 bond and exists in keto form with C8═O3 bond length of 1.216 (2) Å, which is very close to a normal C═O bond length 1.21 Å (Allen et al., 1987).

In the crystal, approximately 5% of molecules of the title hydrazide are replaced by molecules of its 6-bromo isomer, and the Br1B atom of this admixture molecule was included in the refinement. Since the molecule of 6-bromo isomer is likely nonplanar due to sterical tensions, it does not occupy exactly the same position as the molecule of 5-bromo isomer. As a result, Br1B deviates by 0.58 (4) Å from the mean plane of C1–C6 benzene ring, and the distance C1—Br1B is 1.67 (5) Å, that is much smaller than the typical bond length C—Br. On this reason, geometric parameters involving Br1B are not included in the cif-file.

Parallel arrangement of molecules in crystal is shown in Fig. 2. Adjacent molecules are linked through classical N—H···O and O—H···O hydrogen bonds, and a C—H···π interaction between one of the methyl H atoms and the phenyl ring of the adjacent molecule is also observed (see Table 1, Fig. 3). Weak π···π interactions are also present with a shortest separation between benzene ring centroids of 4.973 (3) Å.

Experimental

The title compound was prepared by adapting a reported procedure (Emmanuel et al., 2011; Mangalam & Kurup, 2011) by refluxing a mixture of methanolic solutions of 4-methoxybenzhydrazide (0.1661 g, 1 mmol) and 5-bromo-3-methoxysalicylaldehyde (0.2309 g, 1 mmol) for 4 h. The formed crystals were collected, washed with few drops of methanol and dried over P₄O₁₀in vacuo. Single crystals of the title compound suitable for X-ray analysis were obtained by slow evaporation from its methanolic solution. They contains approximately 5% of the 6-bromo isomer of the title compound.