5-Methyl-3-[1-(2-pyridylmeth­yl)-1H-benzimidazol-2-ylmeth­yl]isoxazole

Doumbia, M.L.; Bouhfid, R.; Essassi, E.M.; El Ammari, L.

doi:10.1107/S1600536809040100

organic compounds

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ISSN: 2056-9890

Volume 65| Part 11| November 2009| Pages o2714-o2715

https://doi.org/10.1107/S1600536809040100

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5-Methyl-3-[1-(2-pyridylmethyl)-1H-benzimidazol-2-ylmethyl]isoxazole

Mohamadou Lamine Doumbia,^a Rachid Bouhfid,^b El Mokhtar Essassi ^a ‡ and Lahcen El Ammari ^c ^*

^aLaboratoire de Chimie Organique Hétérocyclique, Pôle de compétences, Pharmacochimie, Av Ibn Battouta, BP 1014, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco, ^bINANOTECH, Rabat, Morocco, and ^cLaboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V-Agdal, Avenue Ibn Battouta, BP. 1014, Rabat, Morocco
^*Correspondence e-mail: l_elammari@fsr.ac.ma

(Received 30 September 2009; accepted 1 October 2009; online 10 October 2009)

The title compound, C₁₈H₁₆N₄O, is built up from fused six- and five-membered rings linked to a five-membered isoxazole ring and to a six-membered pyridine ring through a CH₂ group. The fused-ring system is essentially planar, with a maximum deviation of 0.019 (1) Å. It forms interplanar angles of 70.03 (7)° with the isoxazole ring and 81.68 (7)° with the pyridine ring; the two latter rings are also planar, the maximum deviations from the mean planes being 0.0028 (15) and 0.0047 (12) Å, respectively. In the crystal, weak intermolecular non-classical C—H⋯N hydrogen bonds link the molecules, forming a zigzag-like chain parallel to the b axis. A weak intramolecular C—H⋯N hydrogen bond may help to define the conformation of the molecule.

Related literature

Isoxazoles and their derivatives are key intermediates for the preparation of products which mimics natural compounds, see: Baraldi et al. (1987 ). For their biological activity, see: Boros et al. (2006 ); Desai & Desai (2006 ); Eddington et al. (2002 ); Kang et al. (2000 ); Ko et al. (1998 ); Lee & Kim (2002 ); Sbai et al. (2003 ).

Experimental

Crystal data

C₁₈H₁₆N₄O
M_r = 304.35
Monoclinic, P 2₁ /n
a = 11.0761 (2) Å
b = 8.6535 (1) Å
c = 16.5920 (3) Å
β = 103.136 (1)°
V = 1548.68 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.28 × 0.16 × 0.06 mm

Data collection

Bruker X8 Kappa APEX II diffractometer
Absorption correction: none
29777 measured reflections
3567 independent reflections
2460 reflections with I > 2σ(I)
R_int = 0.047

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.105
S = 1.01
3567 reflections
214 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯N4ⁱ	0.93	2.52	3.385 (2)	155
C12—H12B⋯N1	0.97	2.60	3.479 (2)	151
Symmetry code: (i) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT (Bruker, 2005); 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 for Windows (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536809040100/dn2494sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809040100/dn2494Isup2.hkl

checkCIF report

Comment top

Isoxazoles and their derivatives are key intermediates for the preparation of products which mimics natural compounds (Baraldi et al., 1987). They have long been targeted in synthetic investigation for their known biological activities and pharmacological properties such as antiviral (Lee & Kim, 2002), anticonvulsant (Eddington et al., 2002), anti-inflammatory (Ko et al., 1998), and anti-bacterial activity (Kang et al., 2000). Also, varied pharmacological and chelating properties are associated with benzimidazole derivatives and pyridine (Sbai et al., 2003, Desai & Desai, 2006, Boros et al. 2006). Thus it is expected that the association of benzimidazole and pyridine moiety with the isoxazole system would affect significantly the biological and complexing properties.

The molecule is built up from fused six and five-membered rings linked together to a five-membered isoxazole ring and to six-membered pyridine ring through a CH₂ chain (Fig. 1). The fused ring system is essentially planar, with maximum deviation of -0.008 (2) and -0.019 (1) Å for atoms C4 and C12 respectively. It forms interplanar angles of 70.03 (7)° with the isoxazole ring and 81.68 (7)°t with the pyridine ring. These two last rings are also planar with maximum deviation from the mean planes being 0.0028 (15) at C1 and 0.0047 (12) at N4 for the isoxazole and the pyridine ring respectively.

There is a a weak intermolecular non classical C—H···N hydrogen bond linking the molecules to form a chain parallel to the (Table 1, Fig. 1). Weak intramolecular hydrogen bonds C—H···N may be responsible for the conformation of the molecule (Fig. 1, Table 1).

Related literature top

Isoxazoles and their derivatives are key intermediates for the preparation of products which mimics natural compounds, see: Baraldi et al. (1987) . For their biological activity, see: Boros et al. (2006); Desai & Desai (2006); Eddington et al. (2002); Kang et al. (2000); Ko et al. (1998); Lee & Kim (2002); Sbai et al. (2003).

Experimental top

To a solution of 3-((1H-benzimidazol-2-yl)methyl)-5-methylisoxazole (0.85 g, 4 mmol) in DMF (20 ml) was added (0.60 g, 4.4 mmol) of K2CO3. The mixture was stirred for 10 min at rt, and then 2-(chloromethyl)pyridine hydrochloride (0.72 g, 4.4 mmol) was added to the mixture. The reaction mixture was stirred at room temperature for 24 h. whereupon a white solid was deposited. The solid was filtered off, and the filtrate was concentrated under reduced pressure. The residue was subjected to a column chromatography (silica gel, hexane/ethyl acetate, 7:3, v/v) to give 5-methyl-3-((1-(pyridin-2-ylmethyl)-1H-benzimidazol-2-yl)methyl)isoxazole as a white crystal in 65% yield (0.79 g).

Structure description top

Isoxazoles and their derivatives are key intermediates for the preparation of products which mimics natural compounds, see: Baraldi et al. (1987) . For their biological activity, see: Boros et al. (2006); Desai & Desai (2006); Eddington et al. (2002); Kang et al. (2000); Ko et al. (1998); Lee & Kim (2002); Sbai et al. (2003).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. : Molecular view with the atom labeling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. H bonds are shown as dashed lines.
	Fig. 2. : Partial packing view showing the formation of a chain through C—H···N hydrogen bond shown as dashed lines. H atoms not involved in hydrogen bondings have been omitted for clarity. [Symmetry code: (i) 1/2 - x, y - 1/2, 1/2 - z]

5-Methyl-3-[1-(2-pyridylmethyl)-1H-benzimidazol-2-ylmethyl]isoxazole top

Crystal data top

C₁₈H₁₆N₄O	F(000) = 640
M_r = 304.35	D_x = 1.305 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3567 reflections
a = 11.0761 (2) Å	θ = 2.5–27.5°
b = 8.6535 (1) Å	µ = 0.09 mm⁻¹
c = 16.5920 (3) Å	T = 298 K
β = 103.136 (1)°	Block, white
V = 1548.68 (4) Å³	0.28 × 0.16 × 0.06 mm
Z = 4

Data collection top

Bruker X8 APEX Diffractometer	2460 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.047
Graphite monochromator	θ_max = 27.5°, θ_min = 2.5°
φ and ω scans	h = −14→14
29777 measured reflections	k = −11→11
3567 independent reflections	l = −21→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.040	H-atom parameters constrained
wR(F²) = 0.105	w = 1/[σ²(F_o²) + (0.0445P)² + 0.2578P] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max < 0.001
3567 reflections	Δρ_max = 0.15 e Å⁻³
214 parameters	Δρ_min = −0.14 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0099 (13)

Crystal data top

C₁₈H₁₆N₄O	V = 1548.68 (4) Å³
M_r = 304.35	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 11.0761 (2) Å	µ = 0.09 mm⁻¹
b = 8.6535 (1) Å	T = 298 K
c = 16.5920 (3) Å	0.28 × 0.16 × 0.06 mm
β = 103.136 (1)°

Data collection top

Bruker X8 APEX Diffractometer	2460 reflections with I > 2σ(I)
29777 measured reflections	R_int = 0.047
3567 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.105	H-atom parameters constrained
S = 1.01	Δρ_max = 0.15 e Å⁻³
3567 reflections	Δρ_min = −0.14 e Å⁻³
214 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
O1	0.35108 (10)	−0.03671 (13)	0.02360 (6)	0.0584 (3)
N1	0.28238 (12)	0.07631 (17)	0.05503 (8)	0.0587 (4)
N2	0.14275 (11)	0.00694 (14)	0.28340 (7)	0.0462 (3)
N3	0.02122 (11)	0.07134 (13)	0.16088 (7)	0.0421 (3)
N4	−0.03858 (11)	0.38647 (14)	0.14258 (7)	0.0472 (3)
C1	0.41164 (13)	−0.12534 (17)	0.08719 (9)	0.0461 (4)
C2	0.38459 (14)	−0.07581 (17)	0.15741 (9)	0.0467 (4)
H2	0.4130	−0.1163	0.2102	0.056*
C3	0.30411 (13)	0.05044 (16)	0.13448 (9)	0.0438 (3)
C4	0.24511 (14)	0.15139 (17)	0.18861 (9)	0.0519 (4)
H4B	0.3067	0.1774	0.2384	0.061 (5)*
H4A	0.2178	0.2469	0.1595	0.067 (5)*
C5	0.13705 (13)	0.07608 (15)	0.21254 (8)	0.0414 (3)
C6	0.02351 (13)	−0.04756 (15)	0.27876 (8)	0.0428 (3)
C7	−0.02328 (16)	−0.13135 (18)	0.33632 (10)	0.0559 (4)
H7	0.0275	−0.1608	0.3866	0.067*
C8	−0.14703 (17)	−0.1693 (2)	0.31653 (11)	0.0655 (5)
H8	−0.1803	−0.2249	0.3543	0.079*
C9	−0.22337 (16)	−0.1265 (2)	0.24140 (11)	0.0657 (5)
H9	−0.3067	−0.1538	0.2302	0.079*
C10	−0.17938 (14)	−0.04485 (19)	0.18304 (10)	0.0553 (4)
H10	−0.2307	−0.0165	0.1327	0.066*
C11	−0.05416 (13)	−0.00683 (15)	0.20323 (8)	0.0416 (3)
C12	−0.01820 (15)	0.13746 (17)	0.07846 (8)	0.0469 (4)
H12A	−0.0812	0.0708	0.0458	0.052 (4)*
H12B	0.0521	0.1375	0.0526	0.056 (4)*
C13	−0.06934 (12)	0.29955 (15)	0.07513 (7)	0.0380 (3)
C14	−0.08168 (16)	0.53187 (18)	0.13659 (10)	0.0568 (4)
H14	−0.0619	0.5940	0.1835	0.068*
C15	−0.15277 (16)	0.5944 (2)	0.06597 (11)	0.0610 (4)
H15	−0.1801	0.6961	0.0650	0.073*
C16	−0.18271 (15)	0.5037 (2)	−0.00321 (10)	0.0600 (4)
H16	−0.2305	0.5428	−0.0524	0.072*
C17	−0.14106 (13)	0.35385 (18)	0.00120 (9)	0.0496 (4)
H17	−0.1608	0.2897	−0.0449	0.060*
C18	0.48944 (16)	−0.2503 (2)	0.06534 (11)	0.0633 (4)
H18A	0.4381	−0.3218	0.0286	0.095*
H18B	0.5309	−0.3033	0.1147	0.095*
H18C	0.5499	−0.2068	0.0386	0.095*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0632 (7)	0.0749 (8)	0.0368 (6)	0.0062 (6)	0.0106 (5)	0.0119 (5)
N1	0.0609 (8)	0.0670 (9)	0.0474 (8)	0.0091 (7)	0.0107 (6)	0.0143 (6)
N2	0.0487 (7)	0.0438 (7)	0.0433 (7)	0.0026 (5)	0.0050 (5)	0.0042 (5)
N3	0.0491 (7)	0.0372 (6)	0.0381 (6)	0.0050 (5)	0.0062 (5)	0.0019 (5)
N4	0.0572 (7)	0.0463 (7)	0.0355 (6)	0.0096 (6)	0.0050 (5)	−0.0026 (5)
C1	0.0454 (8)	0.0521 (9)	0.0390 (8)	−0.0074 (7)	0.0056 (6)	0.0096 (6)
C2	0.0527 (8)	0.0491 (8)	0.0355 (7)	−0.0054 (7)	0.0040 (6)	0.0085 (6)
C3	0.0440 (8)	0.0443 (8)	0.0414 (8)	−0.0110 (6)	0.0059 (6)	0.0065 (6)
C4	0.0578 (9)	0.0440 (8)	0.0526 (9)	−0.0097 (7)	0.0100 (7)	−0.0012 (7)
C5	0.0484 (8)	0.0321 (7)	0.0420 (8)	0.0014 (6)	0.0068 (6)	−0.0029 (6)
C6	0.0475 (8)	0.0373 (7)	0.0432 (8)	0.0054 (6)	0.0096 (6)	−0.0002 (6)
C7	0.0647 (10)	0.0542 (9)	0.0504 (9)	0.0019 (8)	0.0161 (8)	0.0061 (7)
C8	0.0718 (12)	0.0661 (11)	0.0664 (11)	−0.0091 (9)	0.0321 (9)	−0.0011 (9)
C9	0.0516 (10)	0.0804 (12)	0.0689 (11)	−0.0106 (9)	0.0216 (9)	−0.0147 (10)
C10	0.0481 (9)	0.0634 (10)	0.0520 (9)	0.0048 (7)	0.0063 (7)	−0.0097 (8)
C11	0.0475 (8)	0.0354 (7)	0.0419 (8)	0.0058 (6)	0.0100 (6)	−0.0044 (6)
C12	0.0575 (9)	0.0478 (8)	0.0337 (7)	0.0062 (7)	0.0068 (6)	−0.0024 (6)
C13	0.0392 (7)	0.0435 (8)	0.0306 (7)	0.0010 (6)	0.0067 (5)	0.0019 (6)
C14	0.0714 (11)	0.0463 (9)	0.0523 (9)	0.0088 (8)	0.0136 (8)	−0.0049 (7)
C15	0.0641 (10)	0.0475 (9)	0.0717 (12)	0.0137 (8)	0.0164 (9)	0.0134 (8)
C16	0.0548 (9)	0.0641 (10)	0.0551 (10)	0.0061 (8)	0.0001 (7)	0.0237 (8)
C17	0.0514 (9)	0.0563 (9)	0.0365 (8)	−0.0040 (7)	0.0004 (6)	0.0035 (7)
C18	0.0676 (11)	0.0635 (10)	0.0621 (10)	0.0020 (8)	0.0216 (9)	0.0026 (8)

Geometric parameters (Å, º) top

O1—C1	1.3526 (17)	C7—H7	0.9300
O1—N1	1.4100 (17)	C8—C9	1.388 (2)
N1—C3	1.3044 (17)	C8—H8	0.9300
N2—C5	1.3079 (17)	C9—C10	1.374 (2)
N2—C6	1.3880 (18)	C9—H9	0.9300
N3—C5	1.3720 (17)	C10—C11	1.390 (2)
N3—C11	1.3840 (18)	C10—H10	0.9300
N3—C12	1.4548 (16)	C12—C13	1.5090 (19)
N4—C13	1.3270 (16)	C12—H12A	0.9700
N4—C14	1.3414 (19)	C12—H12B	0.9700
C1—C2	1.338 (2)	C13—C17	1.3833 (18)
C1—C18	1.478 (2)	C14—C15	1.366 (2)
C2—C3	1.407 (2)	C14—H14	0.9300
C2—H2	0.9300	C15—C16	1.368 (2)
C3—C4	1.504 (2)	C15—H15	0.9300
C4—C5	1.494 (2)	C16—C17	1.372 (2)
C4—H4B	0.9700	C16—H16	0.9300
C4—H4A	0.9700	C17—H17	0.9300
C6—C7	1.390 (2)	C18—H18A	0.9600
C6—C11	1.3945 (19)	C18—H18B	0.9600
C7—C8	1.375 (2)	C18—H18C	0.9600

C1—O1—N1	108.57 (11)	C10—C9—H9	119.0
C3—N1—O1	105.28 (11)	C8—C9—H9	119.0
C5—N2—C6	104.75 (11)	C9—C10—C11	116.48 (15)
C5—N3—C11	106.49 (11)	C9—C10—H10	121.8
C5—N3—C12	127.86 (12)	C11—C10—H10	121.8
C11—N3—C12	125.63 (12)	N3—C11—C10	132.63 (13)
C13—N4—C14	116.77 (12)	N3—C11—C6	105.05 (12)
C2—C1—O1	109.15 (13)	C10—C11—C6	122.32 (14)
C2—C1—C18	134.95 (14)	N3—C12—C13	115.46 (11)
O1—C1—C18	115.90 (13)	N3—C12—H12A	108.4
C1—C2—C3	105.48 (12)	C13—C12—H12A	108.4
C1—C2—H2	127.3	N3—C12—H12B	108.4
C3—C2—H2	127.3	C13—C12—H12B	108.4
N1—C3—C2	111.51 (13)	H12A—C12—H12B	107.5
N1—C3—C4	119.88 (13)	N4—C13—C17	122.74 (13)
C2—C3—C4	128.61 (13)	N4—C13—C12	118.28 (11)
C5—C4—C3	112.85 (12)	C17—C13—C12	118.90 (12)
C5—C4—H4B	109.0	N4—C14—C15	124.12 (15)
C3—C4—H4B	109.0	N4—C14—H14	117.9
C5—C4—H4A	109.0	C15—C14—H14	117.9
C3—C4—H4A	109.0	C14—C15—C16	118.38 (15)
H4B—C4—H4A	107.8	C14—C15—H15	120.8
N2—C5—N3	113.28 (12)	C16—C15—H15	120.8
N2—C5—C4	124.10 (13)	C15—C16—C17	118.87 (14)
N3—C5—C4	122.62 (12)	C15—C16—H16	120.6
N2—C6—C7	129.63 (13)	C17—C16—H16	120.6
N2—C6—C11	110.42 (12)	C16—C17—C13	119.12 (14)
C7—C6—C11	119.95 (14)	C16—C17—H17	120.4
C8—C7—C6	117.89 (15)	C13—C17—H17	120.4
C8—C7—H7	121.1	C1—C18—H18A	109.5
C6—C7—H7	121.1	C1—C18—H18B	109.5
C7—C8—C9	121.43 (16)	H18A—C18—H18B	109.5
C7—C8—H8	119.3	C1—C18—H18C	109.5
C9—C8—H8	119.3	H18A—C18—H18C	109.5
C10—C9—C8	121.93 (16)	H18B—C18—H18C	109.5

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N4ⁱ	0.93	2.52	3.385 (2)	155
C12—H12B···N1	0.97	2.60	3.479 (2)	151

Symmetry code: (i) −x+1/2, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₈H₁₆N₄O
M_r	304.35
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	298
a, b, c (Å)	11.0761 (2), 8.6535 (1), 16.5920 (3)
β (°)	103.136 (1)
V (Å³)	1548.68 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.28 × 0.16 × 0.06

Data collection
Diffractometer	Bruker X8 APEX Diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	29777, 3567, 2460
R_int	0.047
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.105, 1.01
No. of reflections	3567
No. of parameters	214
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.15, −0.14

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N4ⁱ	0.93	2.52	3.385 (2)	155
C12—H12B···N1	0.97	2.60	3.479 (2)	151

Symmetry code: (i) −x+1/2, y−1/2, −z+1/2.

Footnotes

‡Present address: INANOTECH, Rabat, Morocco.

Acknowledgements

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.

References

Baraldi, P. G., Barco, A., Benetti, S., Pollini, G. P. & Simoni, D. (1987). Synthesis, pp. 857–869. CrossRef Google Scholar
Boros, E. E., Johns, B. A., Garvey, E. P., Koble, C. S. & Miller, W. H. (2006). Bioorg. Med. Chem. Lett. 16, 5668–5672. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2005). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Desai, K. G. & Desai, K. R. (2006). Bioorg. Med. Chem. 14, 8271–8279. Web of Science CrossRef PubMed CAS Google Scholar
Eddington, N. D., Cox, D. S., Roberts, R. R., Butcher, R. J., Edafiogho, I. O., Stables, J. P., Cooke, N., Goodwin, A. M., Smith, C. A. & Scott, K. R. (2002). Eur. J. Med. Chem. 37, 635–648. Web of Science CSD CrossRef PubMed CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Kang, Y. K., Shin, K. J., Yoo, K. H., Seo, K. J., Hong, C. Y., Lee, C., Park, S. Y., Kim, D. J. & Park, S. W. (2000). Bioorg. Med. Chem. Lett. 10, 95–99. Web of Science CrossRef PubMed CAS Google Scholar
Ko, D.-H., Maponya, M. F., Khalil, M. A., Oriaku, E. T., You, Z. & Lee, J. (1998). Med. Chem. Res. 8, 313–324. Google Scholar
Lee, Y. & Kim, B. H. (2002). Bioorg. Med. Chem. Lett. 12, 1395–1397. Web of Science CrossRef PubMed CAS Google Scholar
Sbai, F., Regragui, R., Essassi, E., Kenz, A. & Pierrot, M. (2003). Acta Cryst. E59, m571–m573. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar