2-(2-Ethoxy­phen­yl)-1H-benzimidazole monohydrate

Navarrete-Vázquez, G.; Moreno-Diaz, H.; Estrada-Soto, S.; Tlahuext, H.

doi:10.1107/S1600536807047496

2-(2-Ethoxyphenyl)-1H-benzimidazole monohydrate

G. Navarrete-Vázquez, H. Moreno-Diaz, S. Estrada-Soto and H. Tlahuext

In the title compound, C₁₅H₁₄N₂O·H₂O, the dihedral angle between the benzimidazole ring system and the benzene ring is 6.74 (18)°. The water molecule takes part in the hydrogen-bonding network (N

H—O—H

N), connecting neighboring benzimidazole molecules. The packing is further stabilized by a π–π interaction between two adjacent benzimidazole ring systems, with a distance between the centroids of the benzene rings of 3.8315 (12) Å.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807047496/is2213sup1.cif Contains datablocks I, global
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536807047496/is2213Isup2.hkl Contains datablock I

CCDC reference: 667273

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Key indicators

Single-crystal X-ray study
T = 297 K
Mean (C-C) = 0.002 Å
R factor = 0.037
wR factor = 0.093
Data-to-parameter ratio = 10.2

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Alert level G
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
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   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
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Comment top

Hydrogen bonding and π-π interactions are two of the principal forces which determine structure, self-assembly and recognition in some chemical and biological systems (Lehn, 1990). Benzimidazole and its derivatives are important heterocyclic compounds with versatile pharmacological activities. They have been used as antiparasitic (Navarrete-Vázquez et al., 2003), vasorelaxant and spasmolytic agents (Navarrete-Vázquez et al., 2006; Estrada-Soto et al., 2006), antimicrobial (Özden et al., 2005), antitumoral (Andrzejewska et al., 2002) and antifungal agents (Küçükbay et al., 2003). In our ongoing studies of benzimidazole derivatives as vasorelaxant agents, the compound (I) was prepared by reaction of 1,2-phenylendiamine, with 2-ethoxybenzaldehyde under microwave irradiation.

The whole molecule is non planar; the dihedral angle between benzimidazole moiety and the aryl group is 6.74 (18)° (Fig. 1). The packing can be expressed as a stacking of sheets running along a axis. The sheets consist of a two-dimensional hydrogen bonding network (Fig. 2), which is described by the graph set R²₄(8) (Bernstein et al., 1995). The packing is further stabilized by an offset π-π interaction between two adjacent imidazole molecules, with a distance between the centroids of the C1—C6 and C8—C13 benzene rings (Cg1 and Cg2) of 3.8315 (12) Å (Hunter, 1994; Desiraju, 1991).

Related literature top

For related literature, see: Andrzejewska et al. (2002); Bernstein et al. (1995); Desiraju (1991); Estrada-Soto et al. (2006); Hunter (1994); Küçükbay et al. (2003); Lehn (1990); Navarrete-Vázquez et al. (2003, 2006); Özden et al. (2005).

Experimental top

A mixture of 1,2.phenylendiamine (1.0 g, 9.2 mmol), 2-ethoxybenzaldehyde (1.52 g, 10 mmol), and sodium metabisulfite (1.92 g, 10 mmol) was stirred and introduced in an open Erlenmeyer Pyrex flask. The mixture was irradiated in a household microwave oven (1000 W) for 40–50 s. After irradiation the mixture was poured onto cold water. The precipitate was collected by filtration, washed with water and dried to give a white solid (m.p. 149.4–150.3 °C). Single crystals of (I) were obtained from a methanol-water (9:1 v/v) solution (yield 1.93 g, 88%).

Structure description top

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT (Bruker, 2000); software used to prepare material for publication: SHELXTL-NT (Bruker, 2000) and PLATON (Spek, 2003).

Figures top

	Fig. 1. Perspective view of (I). Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. Crystal packing of (I). The molecules are linked into chains along the a axis by intermolecular N···H—O—H···N hydrogen bonds.

2-(2-Ethoxyphenyl)-1H-benzimidazole monohydrate top

Crystal data top

C₁₅H₁₄N₂O·H₂O	F(000) = 544
M_r = 256.30	D_x = 1.320 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 202 reflections
a = 7.9148 (16) Å	θ = 3.6–27.8°
b = 12.307 (3) Å	µ = 0.09 mm⁻¹
c = 13.737 (3) Å	T = 297 K
β = 105.49 (3)°	Plate, colourless
V = 1289.5 (5) Å³	0.27 × 0.23 × 0.19 mm
Z = 4

Data collection top

Bruker SMART APEX 1000 CCD area-detector diffractometer	2404 independent reflections
Radiation source: fine-focus sealed tube	2243 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
Detector resolution: 8.3 pixels mm^-1	θ_max = 25.5°, θ_min = 2.3°
φ and ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −11→14
T_min = 0.97, T_max = 0.98	l = −16→16
7949 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.037	Hydrogen site location: difference Fourier map
wR(F²) = 0.093	All H-atom parameters refined
S = 1.09	w = 1/[σ²(F_o²) + (0.0429P)² + 0.4998P] where P = (F_o² + 2F_c²)/3
2404 reflections	(Δ/σ)_max < 0.001
236 parameters	Δρ_max = 0.24 e Å⁻³
0 restraints	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₁₅H₁₄N₂O·H₂O	V = 1289.5 (5) Å³
M_r = 256.30	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.9148 (16) Å	µ = 0.09 mm⁻¹
b = 12.307 (3) Å	T = 297 K
c = 13.737 (3) Å	0.27 × 0.23 × 0.19 mm
β = 105.49 (3)°

Data collection top

Bruker SMART APEX 1000 CCD area-detector diffractometer	2404 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	2243 reflections with I > 2σ(I)
T_min = 0.97, T_max = 0.98	R_int = 0.025
7949 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	0 restraints
wR(F²) = 0.093	All H-atom parameters refined
S = 1.09	Δρ_max = 0.24 e Å⁻³
2404 reflections	Δρ_min = −0.25 e Å⁻³
236 parameters

Special details top

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	−0.05937 (16)	0.47716 (10)	0.84284 (9)	0.0162 (3)
C2	−0.19320 (17)	0.53173 (11)	0.77306 (10)	0.0193 (3)
C3	−0.14220 (18)	0.61769 (12)	0.72245 (10)	0.0218 (3)
C4	0.03411 (18)	0.64841 (11)	0.74050 (10)	0.0218 (3)
C5	0.16608 (18)	0.59365 (11)	0.80924 (10)	0.0202 (3)
C6	0.11740 (16)	0.50595 (10)	0.86018 (9)	0.0164 (3)
C7	0.11019 (16)	0.36787 (10)	0.95614 (9)	0.0155 (3)
C8	0.16812 (16)	0.28158 (10)	1.03137 (9)	0.0167 (3)
C9	0.05569 (16)	0.20205 (11)	1.05285 (9)	0.0176 (3)
C10	0.12096 (18)	0.12488 (11)	1.12797 (10)	0.0209 (3)
C11	0.29693 (18)	0.12576 (11)	1.18019 (10)	0.0223 (3)
C12	0.41012 (18)	0.20236 (11)	1.15903 (10)	0.0221 (3)
C13	0.34549 (17)	0.27953 (11)	1.08530 (10)	0.0199 (3)
C14	−0.23200 (18)	0.12119 (12)	1.01266 (11)	0.0232 (3)
C15	−0.40148 (19)	0.13433 (13)	0.93175 (12)	0.0267 (3)
H1	−0.152 (2)	0.3559 (13)	0.9145 (11)	0.022 (4)*
H2	−0.316 (2)	0.5117 (12)	0.7609 (11)	0.021 (4)*
H3	−0.232 (2)	0.6590 (13)	0.6738 (12)	0.022 (4)*
H4	0.0671 (19)	0.7099 (13)	0.7035 (11)	0.022 (4)*
H5	0.289 (2)	0.6147 (12)	0.8229 (11)	0.020 (4)*
H10	0.044 (2)	0.0704 (13)	1.1430 (11)	0.022 (4)*
H11	0.339 (2)	0.0721 (13)	1.2320 (12)	0.024 (4)*
H12	0.537 (2)	0.2018 (12)	1.1952 (11)	0.022 (4)*
H13	0.4237 (19)	0.3340 (13)	1.0702 (11)	0.019 (4)*
H2A	0.633 (3)	0.4683 (18)	0.9586 (17)	0.055 (6)*
H14A	−0.250 (2)	0.1309 (13)	1.0802 (13)	0.027 (4)*
H15A	−0.455 (2)	0.2055 (16)	0.9349 (13)	0.040 (5)*
H2B	0.466 (3)	0.4167 (15)	0.9152 (13)	0.039 (5)*
H14B	−0.175 (2)	0.0486 (14)	1.0086 (12)	0.025 (4)*
H15B	−0.383 (2)	0.1216 (14)	0.8638 (14)	0.036 (5)*
H15C	−0.486 (2)	0.0807 (15)	0.9417 (13)	0.039 (5)*
N1	−0.05962 (14)	0.38927 (9)	0.90544 (8)	0.0158 (2)
N2	0.22124 (14)	0.43630 (9)	0.93077 (8)	0.0170 (2)
O1	−0.11533 (11)	0.20526 (8)	0.99718 (7)	0.0200 (2)
O2	0.57838 (13)	0.41862 (8)	0.91144 (7)	0.0239 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0194 (6)	0.0158 (7)	0.0140 (6)	0.0008 (5)	0.0057 (5)	−0.0023 (5)
C2	0.0169 (7)	0.0224 (7)	0.0174 (6)	0.0021 (5)	0.0027 (5)	−0.0010 (5)
C3	0.0244 (7)	0.0220 (7)	0.0174 (6)	0.0052 (6)	0.0028 (5)	0.0020 (5)
C4	0.0280 (7)	0.0189 (7)	0.0191 (7)	−0.0002 (6)	0.0073 (5)	0.0029 (6)
C5	0.0199 (7)	0.0208 (7)	0.0204 (7)	−0.0019 (5)	0.0061 (5)	−0.0006 (5)
C6	0.0174 (6)	0.0176 (7)	0.0137 (6)	0.0010 (5)	0.0032 (5)	−0.0026 (5)
C7	0.0162 (6)	0.0160 (7)	0.0142 (6)	−0.0002 (5)	0.0040 (5)	−0.0033 (5)
C8	0.0188 (6)	0.0173 (7)	0.0144 (6)	0.0016 (5)	0.0052 (5)	−0.0018 (5)
C9	0.0180 (6)	0.0191 (7)	0.0158 (6)	0.0011 (5)	0.0047 (5)	−0.0023 (5)
C10	0.0243 (7)	0.0193 (7)	0.0197 (7)	−0.0012 (6)	0.0069 (5)	0.0017 (5)
C11	0.0257 (7)	0.0216 (7)	0.0183 (7)	0.0049 (6)	0.0040 (5)	0.0037 (6)
C12	0.0191 (7)	0.0251 (8)	0.0204 (7)	0.0030 (6)	0.0023 (5)	0.0006 (6)
C13	0.0192 (7)	0.0201 (7)	0.0203 (7)	−0.0007 (5)	0.0051 (5)	−0.0002 (5)
C14	0.0220 (7)	0.0217 (8)	0.0264 (8)	−0.0046 (6)	0.0069 (6)	0.0037 (6)
C15	0.0210 (7)	0.0244 (8)	0.0325 (8)	−0.0061 (6)	0.0033 (6)	0.0012 (6)
N1	0.0138 (5)	0.0172 (6)	0.0167 (5)	−0.0010 (4)	0.0045 (4)	−0.0003 (4)
N2	0.0168 (5)	0.0176 (6)	0.0161 (5)	−0.0006 (4)	0.0034 (4)	−0.0002 (4)
O1	0.0169 (5)	0.0208 (5)	0.0206 (5)	−0.0040 (4)	0.0022 (4)	0.0037 (4)
O2	0.0179 (5)	0.0276 (6)	0.0264 (5)	−0.0026 (4)	0.0064 (4)	−0.0067 (4)

Geometric parameters (Å, º) top

C1—N1	1.3821 (17)	C9—C10	1.3961 (19)
C1—C2	1.3962 (18)	C10—C11	1.386 (2)
C1—C6	1.4006 (18)	C10—H10	0.965 (16)
C2—C3	1.384 (2)	C11—C12	1.384 (2)
C2—H2	0.969 (15)	C11—H11	0.963 (16)
C3—C4	1.402 (2)	C12—C13	1.3831 (19)
C3—H3	0.977 (16)	C12—H12	0.996 (15)
C4—C5	1.382 (2)	C13—H13	0.972 (16)
C4—H4	0.985 (16)	C14—O1	1.4399 (16)
C5—C6	1.3955 (19)	C14—C15	1.505 (2)
C5—H5	0.974 (15)	C14—H14A	0.984 (16)
C6—N2	1.3873 (17)	C14—H14B	1.008 (17)
C7—N2	1.3292 (17)	C15—H15A	0.979 (19)
C7—N1	1.3641 (17)	C15—H15B	0.994 (19)
C7—C8	1.4673 (18)	C15—H15C	0.977 (19)
C8—C13	1.4016 (19)	N1—H1	0.879 (16)
C8—C9	1.4062 (18)	O2—H2A	0.91 (2)
C9—O1	1.3659 (16)	O2—H2B	0.91 (2)

N1—C1—C2	132.58 (12)	C9—C10—H10	120.0 (9)
N1—C1—C6	105.04 (11)	C12—C11—C10	120.94 (13)
C2—C1—C6	122.36 (12)	C12—C11—H11	120.4 (9)
C3—C2—C1	116.30 (12)	C10—C11—H11	118.7 (9)
C3—C2—H2	121.3 (9)	C13—C12—C11	119.21 (13)
C1—C2—H2	122.4 (9)	C13—C12—H12	119.8 (9)
C2—C3—C4	121.81 (13)	C11—C12—H12	121.0 (9)
C2—C3—H3	119.1 (9)	C12—C13—C8	121.45 (13)
C4—C3—H3	119.1 (9)	C12—C13—H13	119.9 (9)
C5—C4—C3	121.61 (13)	C8—C13—H13	118.7 (9)
C5—C4—H4	118.1 (9)	O1—C14—C15	107.10 (11)
C3—C4—H4	120.3 (9)	O1—C14—H14A	108.2 (9)
C4—C5—C6	117.41 (12)	C15—C14—H14A	111.0 (9)
C4—C5—H5	122.3 (9)	O1—C14—H14B	108.5 (9)
C6—C5—H5	120.3 (9)	C15—C14—H14B	112.1 (9)
N2—C6—C5	129.57 (12)	H14A—C14—H14B	109.8 (13)
N2—C6—C1	109.94 (11)	C14—C15—H15A	112.0 (10)
C5—C6—C1	120.49 (12)	C14—C15—H15B	110.6 (10)
N2—C7—N1	111.97 (11)	H15A—C15—H15B	110.9 (15)
N2—C7—C8	122.62 (11)	C14—C15—H15C	109.6 (11)
N1—C7—C8	125.40 (12)	H15A—C15—H15C	105.9 (14)
C13—C8—C9	118.50 (12)	H15B—C15—H15C	107.6 (14)
C13—C8—C7	117.76 (12)	C7—N1—C1	107.69 (11)
C9—C8—C7	123.74 (12)	C7—N1—H1	125.7 (10)
O1—C9—C10	123.32 (12)	C1—N1—H1	126.5 (10)
O1—C9—C8	116.77 (11)	C7—N2—C6	105.36 (10)
C10—C9—C8	119.91 (12)	C9—O1—C14	118.37 (10)
C11—C10—C9	119.97 (13)	H2A—O2—H2B	105.4 (17)
C11—C10—H10	120.0 (9)

N1—C1—C2—C3	−179.46 (13)	O1—C9—C10—C11	178.94 (12)
C6—C1—C2—C3	−0.97 (19)	C8—C9—C10—C11	−1.0 (2)
C1—C2—C3—C4	−0.2 (2)	C9—C10—C11—C12	0.0 (2)
C2—C3—C4—C5	0.6 (2)	C10—C11—C12—C13	0.6 (2)
C3—C4—C5—C6	0.2 (2)	C11—C12—C13—C8	−0.2 (2)
C4—C5—C6—N2	178.69 (12)	C9—C8—C13—C12	−0.75 (19)
C4—C5—C6—C1	−1.28 (19)	C7—C8—C13—C12	178.61 (12)
N1—C1—C6—N2	0.61 (13)	N2—C7—N1—C1	0.12 (14)
C2—C1—C6—N2	−178.24 (11)	C8—C7—N1—C1	179.17 (11)
N1—C1—C6—C5	−179.41 (11)	C2—C1—N1—C7	178.24 (13)
C2—C1—C6—C5	1.74 (19)	C6—C1—N1—C7	−0.44 (13)
N2—C7—C8—C13	6.74 (18)	N1—C7—N2—C6	0.26 (14)
N1—C7—C8—C13	−172.21 (12)	C8—C7—N2—C6	−178.82 (11)
N2—C7—C8—C9	−173.93 (12)	C5—C6—N2—C7	179.48 (13)
N1—C7—C8—C9	7.1 (2)	C1—C6—N2—C7	−0.54 (14)
C13—C8—C9—O1	−178.58 (11)	C10—C9—O1—C14	−3.68 (18)
C7—C8—C9—O1	2.10 (18)	C8—C9—O1—C14	176.24 (11)
C13—C8—C9—C10	1.34 (18)	C15—C14—O1—C9	−171.40 (11)
C7—C8—C9—C10	−177.98 (12)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1	0.876 (16)	2.153 (16)	2.6848 (16)	118.6 (13)
N1—H1···O2ⁱ	0.876 (16)	2.259 (16)	2.9108 (17)	131.1 (14)
O2—H2A···N2ⁱⁱ	0.91 (2)	2.02 (2)	2.9267 (16)	173 (2)
O2—H2B···N2	0.91 (2)	2.02 (2)	2.9170 (17)	171.2 (16)
C13—H13···N2	0.972 (16)	2.486 (15)	2.8427 (19)	101.4 (10)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y+1, −z+2.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₄N₂O·H₂O
M_r	256.30
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	297
a, b, c (Å)	7.9148 (16), 12.307 (3), 13.737 (3)
β (°)	105.49 (3)
V (Å³)	1289.5 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.27 × 0.23 × 0.19

Data collection
Diffractometer	Bruker SMART APEX 1000 CCD area-detector
Absorption correction	Multi-scan (SADABS; Sheldrick, 2003)
T_min, T_max	0.97, 0.98
No. of measured, independent and observed [I > 2σ(I)] reflections	7949, 2404, 2243
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.093, 1.09
No. of reflections	2404
No. of parameters	236
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.25

Computer programs: SMART (Bruker, 2000), SAINT-Plus (Bruker, 2000), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL-NT (Bruker, 2000) and PLATON (Spek, 2003).