Crystal structure of (5-methyl­imidazo[1,2-a]pyridin-2-yl)methanol

Elaatiaoui, A.; Koudad, M.; Saddik, R.; Benchat, N.; El Ammari, L.

doi:10.1107/S1600536814023022

organic compounds

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ISSN: 2056-9890

Volume 70| Part 11| November 2014| Pages o1189-o1190

doi:10.1107/S1600536814023022

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Crystal structure of (5-methylimidazo[1,2-a]pyridin-2-yl)methanol

Abdelmalik Elaatiaoui,^a ^* Mohammed Koudad,^a Rafik Saddik,^a Noureddine Benchat ^a and Lahcen El Ammari ^b

^aLaboratory of Applied Chemistry and Environments (LCAE), Faculty of Sciences, University Mohammed Premier, Oujda, Morocco, and ^bLaboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V-Agdal, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
^*Correspondence e-mail: abdelmalik_elaatiaoui@yahoo.fr

Edited by H. Stoeckli-Evans, University of Neuchâtel, Switzerland (Received 18 October 2014; accepted 20 October 2014; online 24 October 2014)

In the title compound, C₉H₁₀N₂O, the imidazo[1,2-a]pyridine moiety is approximately planar (r.m.s. deviation = 0.024 Å). The methanol group is nearly perpendicular to its mean plane as indicated by the C—C—C—O and N—C—C—O torsion angles of 80.04 (16) and −96.30 (17)°, respectively. In the crystal, molecules are linked by O—H⋯N hydrogen bonds, forming inversion dimers with an R²₂(10) ring motif. The dimers are liked via C—H⋯O hydrogen bonds, enclosing R²₂(10) ring motifs and forming ribbons along [201]. The ribbons are linked via a number of π–π interactions [centroid–centroid distances vary from 3.4819 (8) to 3.7212 (8) Å], forming a three-dimensional structure.

Keywords: crystal structure; imidazo[1,2-a]pyridine; hydrogen bonding; π–π interactions.

CCDC reference: 1029873

1. Related literature

For the biological activities of derivatives of the title compound, see: Silvestre et al. (1998 ); Hamdouchi et al. (1999 ); Lhassani et al. (1999 ); Ertl et al. (2000 ). For the synthesis, see: Öhler et al. (1983 ); Chavignon et al. (1992 ).

2. Experimental

2.1. Crystal data

C₉H₁₀N₂O
M_r = 162.19
Triclinic, $[P \overline 1]$
a = 7.3637 (2) Å
b = 8.1589 (2) Å
c = 8.3966 (2) Å
α = 62.355 (1)°
β = 67.291 (2)°
γ = 88.386 (2)°
V = 405.14 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.38 × 0.32 × 0.27 mm

2.2. Data collection

Bruker X8 APEX diffractometer
10226 measured reflections
2089 independent reflections
1865 reflections with I > 2σ(I)
R_int = 0.019

2.3. Refinement

R[F² > 2σ(F²)] = 0.043
wR(F²) = 0.123
S = 1.04
2089 reflections
110 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1ⁱ	0.82	1.98	2.7734 (17)	163
C6—H6⋯O1ⁱⁱ	0.93	2.55	3.4395 (18)	160
Symmetry codes: (i) -x, -y+1, -z+1; (ii) -x, -y+2, -z+1.

Data collection: APEX2 (Bruker, 2009 ); cell refinement: SAINT (Bruker, 2009); 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, 2012 ); software used to prepare material for publication: PLATON (Spek, 2009 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1029873

Crystal structure: contains datablock I. DOI: 10.1107/S1600536814023022/su5007sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536814023022/su5007Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536814023022/su5007Isup3.cml

checkCIF report

Comment top

Imidazo[1,2-a]pyridine moieties represent important building blocks in both natural and synthetic bioactive compounds, which have been shown to possess diverse therapeutic activities (Silvestre et al., 1998; Hamdouchi et al., 1999; Lhassani et al., 1999; Ertl et al., 2000). The synthesis of the title compound is based on the methods described in the literature (Ohler et al., 1983; Chavignon et al., 1992).

The title compound is formed by a fused five- and six-membered rings almost coplanar, with a maximum deviation of 0.029 (1) Å for C7 atom (Fig. 1). The mean plane through the fused ring system (N1/N2/C1-C7) is nearly perpendicular to the hydroxide group as indicated by the torsion angle C6–C7–C8–O1 of -96.30 (17) °.

The cohesion of the crystal structure is ensured by C6—H6···O1 and O1–H1···N1 hydrogen bonds, forming ribbons lying nearly perpendicular to the a axis, as shown in Fig. 2 and Table 1. There are a number of π-π interactions present linking the ribbons and forming a three-dimensional structure [Cg1···Cg1ⁱ = 3.6025 (7) Å, Cg1··· Cg2ⁱ = 3.6610 (8) Å, Cg1··· Cg2ⁱⁱ = 3.7212 (8) Å, and Cg2··· Cg2ⁱⁱ = 3.4819 (8) Å; where Cg1and Cg2 are the centroids of the N1/N2/C1/C6/C7 and N2/C1-C5 rings, respectively; symmetry codes: (i) -x , -y+2, -z; (ii) -x+1, -y+2, -z].

Related literature top

For the biological activities of derivatives of the title compound, see: Silvestre et al. (1998); Hamdouchi et al. (1999); Lhassani et al. (1999); Ertl et al. (2000). For the synthesis, see: Ohler et al. (1983); Chavignon et al. (1992).

Experimental top

The process for the synthesis of (5-methyl-imidazo[1,2-a]pyridine-2-yl) methanol described here occurs in two distinct stages: 1) Condensation of the 6-methylpyridin-2-amine with the ethyl bromopyruvate in boiling methanol. The mixture was then heated at 343 K for 4 h and neutralized at 273 K with Na₂CO₃. The product was extracted with dichloromethane. The organic layer was dried over sodium sulfate and the dichloromethane removed under reduced pressure. The crude product was purified on a silica gel column and identified as ethyl-5-methylimidazo [1,2-a]pyridine -2-carboxylate with 60% yield; 2) The reduction of the ester prepared above with lithium hydride and aluminium at room temperature in methanol for 2 h leads to a solid phase which was recrystallized from ethanol. Colourless crystals of the title compound were obtained with a yield of 67% (m.p. 413 K).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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, 2012); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top

A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

A partial view perpendicular to a axis of the crystal packing of the title compound, showing a layer of molecules linked by hydrogen bonds (dashed lines; see Table 1 for details).

(5-Methylimidazo[1,2-a]pyridin-2-yl)methanol top

Crystal data top

C₉H₁₀N₂O	Z = 2
M_r = 162.19	F(000) = 172
Triclinic, P1	D_x = 1.330 Mg m⁻³
Hall symbol: -p 1	Melting point: 413 K
a = 7.3637 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.1589 (2) Å	Cell parameters from 2089 reflections
c = 8.3966 (2) Å	θ = 2.9–28.7°
α = 62.355 (1)°	µ = 0.09 mm⁻¹
β = 67.291 (2)°	T = 296 K
γ = 88.386 (2)°	Block, colourless
V = 405.14 (2) Å³	0.38 × 0.32 × 0.27 mm

Data collection top

Bruker X8 APEX diffractometer	1865 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.019
Graphite monochromator	θ_max = 28.7°, θ_min = 2.9°
ϕ and ω scans	h = −9→9
10226 measured reflections	k = −11→10
2089 independent reflections	l = −11→11

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)] = 0.043	H-atom parameters constrained
wR(F²) = 0.123	w = 1/[σ²(F_o²) + (0.0645P)² + 0.0845P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
2089 reflections	Δρ_max = 0.24 e Å⁻³
110 parameters	Δρ_min = −0.18 e Å⁻³
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.061 (14)

Crystal data top

C₉H₁₀N₂O	γ = 88.386 (2)°
M_r = 162.19	V = 405.14 (2) Å³
Triclinic, P1	Z = 2
a = 7.3637 (2) Å	Mo Kα radiation
b = 8.1589 (2) Å	µ = 0.09 mm⁻¹
c = 8.3966 (2) Å	T = 296 K
α = 62.355 (1)°	0.38 × 0.32 × 0.27 mm
β = 67.291 (2)°

Data collection top

Bruker X8 APEX diffractometer	1865 reflections with I > 2σ(I)
10226 measured reflections	R_int = 0.019
2089 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	0 restraints
wR(F²) = 0.123	H-atom parameters constrained
S = 1.04	Δρ_max = 0.24 e Å⁻³
2089 reflections	Δρ_min = −0.18 e Å⁻³
110 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	0.23574 (17)	0.88694 (15)	0.02939 (17)	0.0374 (3)
C2	0.3772 (2)	0.8861 (2)	−0.1413 (2)	0.0487 (3)
H2	0.3890	0.7743	−0.1456	0.058*
C3	0.49565 (19)	1.0507 (2)	−0.29887 (19)	0.0502 (3)
H3	0.5907	1.0510	−0.4110	0.060*
C4	0.47630 (19)	1.22086 (19)	−0.29465 (18)	0.0466 (3)
H4	0.5601	1.3318	−0.4038	0.056*
C5	0.33794 (18)	1.22657 (16)	−0.13469 (16)	0.0399 (3)
C9	0.3049 (2)	1.39916 (18)	−0.1173 (2)	0.0565 (4)
H9B	0.3236	1.3850	−0.0049	0.085*
H9A	0.1709	1.4183	−0.1004	0.085*
H9C	0.3987	1.5057	−0.2355	0.085*
C6	0.07560 (16)	1.02021 (15)	0.21002 (15)	0.0363 (3)
H6	0.0311	1.1066	0.2529	0.044*
C7	0.01244 (16)	0.82991 (15)	0.31517 (16)	0.0383 (3)
C8	−0.1332 (2)	0.71513 (18)	0.52658 (18)	0.0496 (3)
H8A	−0.2211	0.7936	0.5652	0.060*
H8B	−0.2151	0.6140	0.5406	0.060*
N1	0.10972 (15)	0.74701 (14)	0.20387 (15)	0.0420 (3)
N2	0.21944 (13)	1.05816 (12)	0.02646 (13)	0.0339 (2)
O1	−0.03554 (17)	0.63769 (13)	0.65406 (14)	0.0566 (3)
H1	−0.0705	0.5229	0.7180	0.085*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0427 (6)	0.0355 (5)	0.0412 (6)	0.0108 (4)	−0.0231 (5)	−0.0201 (4)
C2	0.0558 (7)	0.0532 (7)	0.0519 (7)	0.0214 (6)	−0.0269 (6)	−0.0342 (6)
C3	0.0463 (6)	0.0690 (9)	0.0402 (6)	0.0161 (6)	−0.0178 (5)	−0.0310 (6)
C4	0.0450 (6)	0.0538 (7)	0.0341 (5)	0.0009 (5)	−0.0155 (5)	−0.0170 (5)
C5	0.0445 (6)	0.0379 (6)	0.0335 (5)	0.0009 (4)	−0.0176 (5)	−0.0134 (4)
C9	0.0760 (9)	0.0358 (6)	0.0433 (6)	−0.0035 (6)	−0.0164 (6)	−0.0147 (5)
C6	0.0392 (5)	0.0342 (5)	0.0336 (5)	0.0073 (4)	−0.0146 (4)	−0.0158 (4)
C7	0.0388 (5)	0.0343 (5)	0.0381 (5)	0.0057 (4)	−0.0178 (4)	−0.0139 (4)
C8	0.0488 (7)	0.0407 (6)	0.0411 (6)	0.0028 (5)	−0.0115 (5)	−0.0119 (5)
N1	0.0494 (6)	0.0332 (5)	0.0445 (5)	0.0086 (4)	−0.0222 (4)	−0.0179 (4)
N2	0.0376 (5)	0.0325 (4)	0.0329 (4)	0.0063 (3)	−0.0171 (4)	−0.0151 (4)
O1	0.0880 (7)	0.0361 (5)	0.0419 (5)	0.0043 (4)	−0.0303 (5)	−0.0136 (4)

Geometric parameters (Å, º) top

C1—N1	1.3299 (15)	C9—H9A	0.9600
C1—N2	1.3884 (14)	C9—H9C	0.9600
C1—C2	1.4126 (17)	C6—C7	1.3631 (15)
C2—C3	1.356 (2)	C6—N2	1.3815 (13)
C2—H2	0.9300	C6—H6	0.9300
C3—C4	1.407 (2)	C7—N1	1.3735 (15)
C3—H3	0.9300	C7—C8	1.4907 (16)
C4—C5	1.3576 (17)	C8—O1	1.4154 (16)
C4—H4	0.9300	C8—H8A	0.9700
C5—N2	1.3823 (14)	C8—H8B	0.9700
C5—C9	1.4857 (18)	O1—H1	0.8200
C9—H9B	0.9600

N1—C1—N2	110.57 (10)	H9B—C9—H9C	109.5
N1—C1—C2	131.10 (11)	H9A—C9—H9C	109.5
N2—C1—C2	118.32 (11)	C7—C6—N2	105.70 (10)
C3—C2—C1	119.09 (12)	C7—C6—H6	127.1
C3—C2—H2	120.5	N2—C6—H6	127.1
C1—C2—H2	120.5	C6—C7—N1	111.22 (10)
C2—C3—C4	120.76 (12)	C6—C7—C8	127.34 (11)
C2—C3—H3	119.6	N1—C7—C8	121.36 (11)
C4—C3—H3	119.6	O1—C8—C7	111.84 (10)
C5—C4—C3	121.41 (12)	O1—C8—H8A	109.2
C5—C4—H4	119.3	C7—C8—H8A	109.2
C3—C4—H4	119.3	O1—C8—H8B	109.2
C4—C5—N2	117.59 (11)	C7—C8—H8B	109.2
C4—C5—C9	125.31 (11)	H8A—C8—H8B	107.9
N2—C5—C9	117.10 (10)	C1—N1—C7	105.62 (9)
C5—C9—H9B	109.5	C6—N2—C5	130.27 (10)
C5—C9—H9A	109.5	C6—N2—C1	106.89 (9)
H9B—C9—H9A	109.5	C5—N2—C1	122.79 (10)
C5—C9—H9C	109.5	C8—O1—H1	109.5

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1ⁱ	0.82	1.98	2.7734 (17)	163
C6—H6···O1ⁱⁱ	0.93	2.55	3.4395 (18)	160

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1ⁱ	0.82	1.98	2.7734 (17)	163
C6—H6···O1ⁱⁱ	0.93	2.55	3.4395 (18)	160

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

Acknowledgements

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

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