2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol monohydrate

Mohammed H Al-Douh; Hasnah Osman; Shafida A Hamid; Reza Kia; Hoong-Kun Fun

doi:10.1107/S1600536809010769

. 2009 Mar 28;65(Pt 4):o913–o914. doi: 10.1107/S1600536809010769

2-[1-(2-Hydroxy-3-methoxybenzyl)-1H-benzimidazol-2-yl]-6-methoxyphenol monohydrate

Mohammed H Al-Douh ^a, Hasnah Osman ^a,^‡, Shafida A Hamid ^b, Reza Kia ^c, Hoong-Kun Fun ^c,^*,^§

PMCID: PMC2968983 PMID: 21582616

Abstract

The asymmetric unit of the title compound, C₂₂H₂₀N₂O₄·H₂O, comprises a substituted benzimidazole molecule and a water molecule of crystallization. The dihedral angles between the benzimidazole ring system and the two outer benzene rings are 16.54 (4) and 86.13 (4)°. The dihedral angle between the two hydroxy-substituted benzene rings is 82.20 (5)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds, involving the hydroxy groups and water molecules, form R ₄ ⁴(8) ring motifs, and link symmetry-related molecules into extended chains along the c axis. The crystal structure is further stabilized by weak intermolecular C—H⋯O hydrogen bonds, weak C—H⋯π and π–π stacking [centroid–centroid = 3.6495 (6)–3.7130 (6) Å] interactions. Intramolecular O—H⋯O and O—H⋯N interactions are also present.

Related literature

For hydrogen-bond motifs, see Bernstein et al. (1995 ▶). For the synthesis and bioactivity of benzimidazoles see, for example: Soto et al. (2006 ▶); Vazquez et al. (2006 ▶); Latif et al. (1983 ▶). For related structures, see: Elerman & Kabak (1997 ▶); Liu et al. (2006 ▶); Al-Douh et al. (2006 ▶, 2007 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₂H₂₀N₂O₄·H₂O
M _r = 394.42
Triclinic,
a = 7.5076 (1) Å
b = 9.8557 (1) Å
c = 13.2240 (2) Å
α = 106.306 (1)°
β = 97.135 (1)°
γ = 97.993 (1)°
V = 916.18 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.48 × 0.28 × 0.10 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.952, T _max = 0.990
33715 measured reflections
8009 independent reflections
6304 reflections with I > 2˘I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.133
S = 1.03
8009 reflections
274 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.58 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809010769/lh2793sup1.cif

e-65-0o913-sup1.cif^{(22.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809010769/lh2793Isup2.hkl

e-65-0o913-Isup2.hkl^{(391.8KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.84	1.80	2.5447 (12)	147
O1W—H2W1⋯O1ⁱ	0.84 (2)	2.23 (2)	3.0151 (11)	155 (2)
O2—H2⋯O4	0.84	2.21	2.6650 (11)	114
O2—H2⋯O1Wⁱⁱ	0.84	1.95	2.7401 (11)	155
O1W—H1W1⋯O2ⁱⁱⁱ	0.87 (2)	2.04 (2)	2.8987 (12)	168.5 (19)
C21—H21B⋯O1W^iv	0.98	2.58	3.2762 (16)	128
C22—H22A⋯O3^v	0.98	2.54	3.2071 (14)	126
C22—H22B⋯Cg1^vi	0.98	2.80	3.5497 (13)	133

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) . Cg1 is the centroid of the C15–C20 benzene ring.

Acknowledgments

We thank the Malaysian Government and Universiti Sains Malaysia (USM) for an FRGS grant [304/PKIMIA/638122] to conduct this work. MHA-D thanks the Yemeni Government and Hadhramout University of Science and Technology (HUST) for financial scholarship support. HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

Many benzimidazoles are pharmaceutical agents and are used widely in biological system applications which enable important synthetic strategies in drug discovery. Phenolic and anisolic benzimidazole derivatives have been synthesized and evaluated for vasodilator and antihypertensive activity (Soto et al., 2006), while other alkyloxyaryl benzimidazole derivatives have been tested for the spasmolytic activity (Vazquez et al., 2006). Latif et al. have developed the reactions of some phenolic aldehydes with o- phenylenediamine in great details and managed to isolate the title compound (Latif et al., 1983). In view of the above, we have obtained the title compound (I), derived from benzimidazole and a bis-Schiff base compound and have determined its crystsal structure herein.

The bond lengths and angles in (I) are consistent with those common to related reported structures (Elerman & Kabak, 1997; Liu et al., 2006). The molecular structure of (I) is shown in Fig. 1. Intramolecular O—H···O and O—H···N hydrogen bonds generate five and six membered rings with S(5) and S(6) ring motifs respectively (Bernstein et al., 1995). Intermolecular O—H···O hydrogen bonds, involving one of the hydroxy groups and one of the water molecules link neighbouring molecules into chains with R⁴₄(8) ring motifs (Bernstein et al., 1995). The dihedral angles between the benzimidazole ring system and the two outer benzene rings are 16.54 (4) and 86.13 (4)°. The dihedral angle between the two hydroxy substituted benzene rings is 82.20 (5)°. In the crystal structure the molecules are linked together by four-membered O—H···O—H···O—H interactions into 1-D extended chains along the c axis. The crystal structure is further stabilized by intermolecular C—H···O hydrogen bonds, weak intermolecular C—H···π (Table 1; Cg1 is the centroids of the C15–C20 benzene ring), and π-π interactions [Cg2···Cg2^vii = 3.6495 (6) Å; Cg3 ···Cg4^vii = 3.7130 (6) Å; Cg2, Cg3 and Cg4 are the centroids of the N1/C7/N2/C8/C13, C1–C6 and C8–C13 rings].

Experimental

The synthetic method has been described earlier (Al-Douh et al., 2006, 2007), while the single crystals suitable for X-ray diffraction were obtained by evaporation of a methanol solution of (I) at 353 K.