Ethyl 1-sec-butyl-2-(2-hydroxy­phen­yl)-1H-benzimidazole-5-carboxyl­ate 0.25-hydrate

Natarajan Arumugam; Aisyah Saad Abdul Rahim; Hasnah Osman; Madhukar Hemamalini; Hoong-Kun Fun

doi:10.1107/S1600536810015448

. 2010 May 8;66(Pt 6):o1285–o1286. doi: 10.1107/S1600536810015448

Ethyl 1-sec-butyl-2-(2-hydroxyphenyl)-1H-benzimidazole-5-carboxylate 0.25-hydrate

Natarajan Arumugam ^a, Aisyah Saad Abdul Rahim ^a,^‡, Hasnah Osman ^b, Madhukar Hemamalini ^c, Hoong-Kun Fun ^c,^*,^§

PMCID: PMC2979540 PMID: 21579384

Abstract

In the title compound, C₂₀H₂₂N₂O₃·0.25H₂O, the water molecule (occupancy 0.25) is disordered across a crystallographic inversion center. The dihedral angle between the hydroxyphenyl ring and the benzimidazole ring system is 59.31 (9)°. In the crystal structure, molecules are connected by intermolecular O—H⋯N and C—H⋯O hydrogen bonds. The crystal structure is further stabilized by a weak C—H⋯π interaction involving the imidazole ring.

Related literature

For background to benzimidazoles and their biological importance, see: Garuti et al. (2004 ▶); Bonfanti et al. (2008 ▶); Ozden et al. (2008 ▶); Shao et al. (2005 ▶); Blythin et al. (1986 ▶); Snow (2007 ▶). For the synthesis of benzimidazoles, see: Arumugam et al. (2010a ▶,b ▶,c ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₀H₂₂N₂O₃·0.25H₂O
M _r = 342.90
Monoclinic,
a = 7.0484 (11) Å
b = 27.262 (4) Å
c = 9.4673 (14) Å
β = 97.495 (3)°
V = 1803.6 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100 K
0.34 × 0.21 × 0.05 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.971, T _max = 0.996
18277 measured reflections
4738 independent reflections
3152 reflections with I > 2σ(I)
R _int = 0.064

Refinement

R[F ² > 2σ(F ²)] = 0.066
wR(F ²) = 0.232
S = 1.08
4738 reflections
243 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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/S1600536810015448/sj2770sup1.cif

e-66-o1285-sup1.cif^{(21.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810015448/sj2770Isup2.hkl

e-66-o1285-Isup2.hkl^{(227.4KB, hkl)}

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

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

Cg1 is the centroid of the N1,N2,C1,C2,N7 imidazole ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O1⋯N1ⁱ	0.96 (4)	1.75 (4)	2.691 (3)	168 (3)
C14—H14C⋯O1ⁱ	0.96	2.45	3.398 (3)	168
C17—H17A⋯Cg1ⁱⁱ	0.93	2.96	3.734 (3)	142

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

Acknowledgments

NA, ASAR and HO acknowledge Universiti Sains Malaysia (USM) for funding the synthetic chemistry work under Research University Grant (1001/PFARMASI/815026). NA also thanks USM for the award of postdoctoral fellowship. HKF and MH thank the Malaysian Government and USM for the Research University Golden Goose grant No. 1001/PFIZIK/811012 and MH also thanks USM for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

Benzimidazoles belong to one of the well known and most extensively studied class of compounds due to their biological activity such as antitumour (Garuti et al., 2004), antiviral (Bonfanti et al., 2008), antibacterial (Ozden et al., 2008) and analgesic properties (Shao et al., 2005). These derivatives are anti-inflammatory (Blythin et al., 1986) and can be carcinogenic (Snow et al., 2007). As the benzimidazole derivative is of much importance, we have undertaken the X-ray crystal structure determination of the title compound.

The asymmetric unit (Fig. 1) contains an ethyl-1-sec-butyl-2- (2-hydroxyphenyl)-1H-benzimidazole-5-carboxylate molecule and a water molecule(O1W), occupancy 0.25, which is disordered across a crystallographic inversion center (symmetry code = -x, -y+2, -z+1). The dihedral angle between the benzimidazole ring system (N1–N2/C1–C7) and the phenyl ring (C15–C20) is 59.31 (9)° .

In the crystal structure (Fig. 2), molecules are connected by intermolecular O1—H1O1···N1 and C14—H14C···O1 (Table 1) hydrogen bonds. The crystal structure is further stabilized by C—H···π interactions (Table 1), involving the imidazole ring, N1–N2/C1–C2/C7 (centroid Cg1).

Experimental

The title compound was synthesised according to the previous procedure described by us (Arumugam et al., 2010a,b,c). The product was recrystallized from EtOAc to yield the title compound as colourless crystals.