Crystal structure of ethyl 2-chloro-5,8-di­meth­oxy­quinoline-3-carboxyl­ate

Hayour, H.; Bouraiou, A.; Bouacida, S.; Benzerka, S.; Belfaitah, A.

doi:10.1107/S1600536814017309

organic compounds

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Volume 70| Part 9| September 2014| Pages o964-o965

doi:10.1107/S1600536814017309

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Crystal structure of ethyl 2-chloro-5,8-dimethoxyquinoline-3-carboxylate

Hasna Hayour,^a Abdelmalek Bouraiou,^a Sofiane Bouacida,^b,^c ^* Saida Benzerka ^b and Ali Belfaitah ^a

^aLaboratoire des Produits Naturels d'Origine Végétale et de Synthèse Organique, PHYSYNOR, Université Constantine 1, 25000 Constantine, Algeria, ^bUnité de Recherche de Chimie de l'Environnement et Moléculaire Structurale (CHEMS), Université Constantine 1, 25000 , Algeria, and ^cDépartement Sciences de la Matière, Faculté des Sciences Exactes et Sciences de la Nature et de la Vie, Université Oum El Bouaghi, Algeria
^*Correspondence e-mail: bouacida_sofiane@yahoo.fr

Edited by P. C. Healy, Griffith University, Australia (Received 22 July 2014; accepted 28 July 2014; online 1 August 2014)

In the title compound, C₁₄H₁₄ClNO₄, the dihedral angle between the quinoline ring system (r.m.s. deviation = 0.0142 Å) and ester planes is 18.99 (3)°. The C—O—C—C_m (m = methyl) torsion angle is −172.08 (10)°, indicating a trans conformation. In the crystal, the molecules are linked by C—H⋯O and C—H⋯N interactions, generating layers lying parallel to (101). Aromatic π-π stacking [centroid–centroid distances = 3.557 (2) and 3.703 (2)Å] links the layers into a three-dimensional network.

Keywords: crystal structure; quinoline derivatives; ester; hydrogen bonding; π–π stacking.

CCDC reference: 1016211

1. Related literature

For the synthesis and applications of quinoline derivatives, see: Wang et al. (2011 ); Benzerka et al. (2012 ); Valdez et al. (2009 ). For our previous work, see: Bouraiou et al. (2012 ); Hayour et al. (2014 ); Benzerka et al. (2012).

2. Experimental

2.1. Crystal data

C₁₄H₁₄ClNO₄
M_r = 295.71
Triclinic, $[P \overline 1]$
a = 7.512 (4) Å
b = 9.759 (5) Å
c = 9.811 (5) Å
α = 76.071 (10)°
β = 72.021 (10)°
γ = 86.037 (10)°
V = 664.0 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.30 mm⁻¹
T = 150 K
0.25 × 0.14 × 0.12 mm

2.2. Data collection

Bruker APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2002 ) T_min = 0.690, T_max = 0.747
10769 measured reflections
5204 independent reflections
4090 reflections with I > 2σ(I)
R_int = 0.024

2.3. Refinement

R[F² > 2σ(F²)] = 0.036
wR(F²) = 0.103
S = 1.04
5204 reflections
184 parameters
H-atom parameters constrained
Δρ_max = 0.5 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10⋯O3ⁱ	0.93	2.56	3.482 (2)	173
C14—H14C⋯N1ⁱⁱ	0.96	2.61	3.476 (2)	150
Symmetry codes: (i) x-1, y, z+1; (ii) -x+2, -y+1, -z+2.

Data collection: APEX2 (Bruker, 2006 ); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SIR2002 (Burla et al., 2005 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ) and DIAMOND (Brandenburg & Berndt, 2001 ); software used to prepare material for publication: WinGX (Farrugia, 2012).

Supporting information

CCDC reference: 1016211

Crystal structure: contains datablock I. DOI: 10.1107/S1600536814017309/hg5402sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536814017309/hg5402Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536814017309/hg5402Isup3.cml

checkCIF report

Comment top

Quinolines have attracted considerable interest for many years due to their presence in the skeleton of a large number of bioactive compounds and natural products (Wang, et al. 2011), such as antibacterial (Benzerka, et al.2012). in going with our investigation, recently, we have reported the synthesis and structure determination of some new quinoline compounds (Hayour, et al., 2014; Bouraiou, et al. 2012). In this paper, we describe the synthesis and the structure determination of ethyl 2-chloro-5,8-dimethoxyquinoline-3-carboxylate (I) which obtained in one step, by addition of NaCN in presence of manganese dioxide in absolute ethanol to 2-chloro-5,8-dimethoxyquinoline-3-carbaldehyde. The molecular geometry and the atom-numbering scheme of (I) are shown in Fig. 1. In the asymmetric unit of title compound the quinoline ring is four time substituted by two methoxy, one chlore and one ethyl carboxylate. The two rings of quinolyl moiety are fused in an axial fashion and form dihedral angle of 1.75 (3) Å. The crystal packing can be described as double layers parallel to (101) plane, along the b axis (Fig. 2). It is stabilized by intermolecular hydrogen bond (N—H···O and C—H···O) and strong π–π stacking, resulting in the formation of infinite a three-dimensional network linking these layers together and reinforces cohesion of the structure (Fig. 2). Hydrogen-bonding parameters are listed in Table 1.

Related literature top

For the synthesis and applications of quinoline derivatives, see: Wang et al. (2011); Benzerka et al. (2012); Valdez et al. (2009). For our previous work, see: Bouraiou et al. (2012); Hayour et al. (2014); Benzerka et al. (2012).

Experimental top

To a cold solution of NaCN (3 mmol) in absolute ethanol (15 mL), a mixture of 2-chloro-5,8-dimethoxy quinolin-3-carbaldehyde (1 mmol) and manganese dioxide (6.7 mmol) was added at 0°C, then the reaction mixture was stirred at 25°C during 3 h. After complexion, the title compound was obtained by simple filtration through a small column packed with 4 cm of celite and 3 cm of silica gel using CH₂Cl₂ as eluant (Valdez, et al. 2009).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top

	Fig. 1. (Farrugia, 2012) the structure of the title compound with the atomic labelling scheme. Displacement are drawn at the 50% probability level.
	Fig. 2. (Brandenburg & Berndt, 2001) A diagram of the layered crystal packing of (I) viewed down the b axis and showing hydrogen bond [C—H···O in red and C—H···N in black] as dashed line.

Ethyl 2-chloro-5,8-dimethoxyquinoline-3-carboxylate top

Crystal data top

C₁₄H₁₄ClNO₄	Z = 2
M_r = 295.71	F(000) = 308
Triclinic, P1	D_x = 1.479 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.512 (4) Å	Cell parameters from 4109 reflections
b = 9.759 (5) Å	θ = 2.7–34.1°
c = 9.811 (5) Å	µ = 0.30 mm⁻¹
α = 76.071 (10)°	T = 150 K
β = 72.021 (10)°	Prism, colorless
γ = 86.037 (10)°	0.25 × 0.14 × 0.12 mm
V = 664.0 (6) Å³

Data collection top

Bruker APEXII diffractometer	4090 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
CCD rotation images, thin slices scans	θ_max = 34.7°, θ_min = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −11→11
T_min = 0.690, T_max = 0.747	k = −15→15
10769 measured reflections	l = −15→15
5204 independent 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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.103	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0528P)² + 0.079P] where P = (F_o² + 2F_c²)/3
5204 reflections	(Δ/σ)_max = 0.001
184 parameters	Δρ_max = 0.5 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₁₄H₁₄ClNO₄	γ = 86.037 (10)°
M_r = 295.71	V = 664.0 (6) Å³
Triclinic, P1	Z = 2
a = 7.512 (4) Å	Mo Kα radiation
b = 9.759 (5) Å	µ = 0.30 mm⁻¹
c = 9.811 (5) Å	T = 150 K
α = 76.071 (10)°	0.25 × 0.14 × 0.12 mm
β = 72.021 (10)°

Data collection top

Bruker APEXII diffractometer	5204 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	4090 reflections with I > 2σ(I)
T_min = 0.690, T_max = 0.747	R_int = 0.024
10769 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.036	0 restraints
wR(F²) = 0.103	H-atom parameters constrained
S = 1.04	Δρ_max = 0.5 e Å⁻³
5204 reflections	Δρ_min = −0.24 e Å⁻³
184 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	1.27548 (18)	1.02335 (11)	0.38370 (13)	0.0317 (2)
H1B	1.3474	1.0184	0.4504	0.048*
H1A	1.1478	1.0451	0.4304	0.048*
H1C	1.3262	1.0958	0.2965	0.048*
C2	1.28321 (17)	0.88354 (11)	0.34275 (11)	0.0266 (2)
H2A	1.2118	0.8873	0.2747	0.032*
H2B	1.4116	0.8599	0.2961	0.032*
C3	1.21881 (13)	0.64349 (10)	0.46758 (10)	0.01689 (16)
C4	1.11813 (13)	0.54830 (9)	0.61114 (10)	0.01547 (15)
C5	1.14674 (13)	0.39997 (10)	0.64961 (10)	0.01641 (16)
C6	0.92888 (13)	0.37156 (9)	0.87752 (10)	0.01595 (16)
C7	0.83649 (14)	0.28087 (10)	1.01633 (10)	0.01932 (17)
C8	0.82466 (19)	0.05352 (12)	1.17645 (13)	0.0316 (2)
H8A	0.8799	−0.0381	1.176	0.047*
H8B	0.6908	0.0448	1.2073	0.047*
H8C	0.8618	0.0943	1.2434	0.047*
C9	0.70785 (14)	0.33822 (11)	1.12113 (10)	0.02025 (18)
H9	0.6474	0.2795	1.2116	0.024*
C10	0.66446 (13)	0.48421 (11)	1.09552 (10)	0.01941 (17)
H10	0.5761	0.5196	1.1683	0.023*
C11	0.75286 (13)	0.57316 (10)	0.96332 (10)	0.01729 (16)
C12	0.88663 (12)	0.51757 (9)	0.85187 (10)	0.01559 (16)
C13	0.98519 (13)	0.60393 (9)	0.71557 (10)	0.01569 (16)
H13	0.9603	0.7001	0.6955	0.019*
C14	0.61166 (16)	0.78024 (12)	1.03759 (11)	0.0250 (2)
H14A	0.4863	0.7439	1.0691	0.038*
H14B	0.6108	0.8806	0.9999	0.038*
H14C	0.661	0.7598	1.1196	0.038*
N1	1.05905 (11)	0.31542 (8)	0.77389 (9)	0.01767 (15)
O1	1.20348 (11)	0.77897 (8)	0.47853 (8)	0.02506 (16)
O2	0.88630 (12)	0.14209 (8)	1.03191 (8)	0.02716 (17)
O3	1.30129 (11)	0.60788 (8)	0.35513 (8)	0.02479 (16)
O4	0.72630 (11)	0.71537 (8)	0.92457 (8)	0.02404 (16)
Cl1	1.31414 (4)	0.31664 (3)	0.52818 (3)	0.02578 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0359 (6)	0.0187 (5)	0.0298 (5)	−0.0004 (4)	0.0026 (5)	−0.0019 (4)
C2	0.0336 (6)	0.0190 (4)	0.0186 (4)	−0.0029 (4)	0.0014 (4)	0.0003 (3)
C3	0.0171 (4)	0.0168 (4)	0.0160 (4)	−0.0001 (3)	−0.0032 (3)	−0.0043 (3)
C4	0.0161 (4)	0.0154 (4)	0.0144 (4)	0.0003 (3)	−0.0030 (3)	−0.0044 (3)
C5	0.0173 (4)	0.0158 (4)	0.0164 (4)	0.0020 (3)	−0.0038 (3)	−0.0064 (3)
C6	0.0172 (4)	0.0150 (4)	0.0156 (4)	−0.0006 (3)	−0.0043 (3)	−0.0040 (3)
C7	0.0221 (4)	0.0163 (4)	0.0184 (4)	−0.0029 (3)	−0.0048 (3)	−0.0028 (3)
C8	0.0421 (7)	0.0189 (5)	0.0245 (5)	−0.0025 (4)	−0.0018 (5)	0.0024 (4)
C9	0.0207 (4)	0.0213 (4)	0.0160 (4)	−0.0050 (3)	−0.0021 (3)	−0.0024 (3)
C10	0.0176 (4)	0.0231 (4)	0.0160 (4)	−0.0005 (3)	−0.0017 (3)	−0.0060 (3)
C11	0.0174 (4)	0.0179 (4)	0.0157 (4)	0.0019 (3)	−0.0033 (3)	−0.0051 (3)
C12	0.0153 (4)	0.0163 (4)	0.0144 (4)	−0.0002 (3)	−0.0030 (3)	−0.0041 (3)
C13	0.0170 (4)	0.0140 (4)	0.0149 (4)	0.0006 (3)	−0.0030 (3)	−0.0036 (3)
C14	0.0278 (5)	0.0267 (5)	0.0207 (4)	0.0105 (4)	−0.0046 (4)	−0.0120 (4)
N1	0.0199 (4)	0.0154 (3)	0.0174 (3)	0.0006 (3)	−0.0046 (3)	−0.0047 (3)
O1	0.0331 (4)	0.0153 (3)	0.0183 (3)	−0.0012 (3)	0.0037 (3)	−0.0026 (2)
O2	0.0384 (4)	0.0146 (3)	0.0212 (3)	−0.0004 (3)	−0.0009 (3)	−0.0010 (3)
O3	0.0300 (4)	0.0243 (4)	0.0163 (3)	−0.0032 (3)	0.0012 (3)	−0.0075 (3)
O4	0.0294 (4)	0.0186 (3)	0.0183 (3)	0.0073 (3)	0.0005 (3)	−0.0054 (3)
Cl1	0.02904 (13)	0.02190 (12)	0.02243 (12)	0.00813 (9)	−0.00059 (9)	−0.00934 (9)

Geometric parameters (Å, º) top

C1—C2	1.5050 (17)	C7—C9	1.3760 (14)
C1—H1B	0.96	C8—O2	1.4257 (14)
C1—H1A	0.96	C8—H8A	0.96
C1—H1C	0.96	C8—H8B	0.96
C2—O1	1.4534 (13)	C8—H8C	0.96
C2—H2A	0.97	C9—C10	1.4189 (15)
C2—H2B	0.97	C9—H9	0.93
C3—O3	1.2062 (12)	C10—C11	1.3722 (14)
C3—O1	1.3463 (13)	C10—H10	0.93
C3—C4	1.4928 (13)	C11—O4	1.3656 (13)
C4—C13	1.3796 (13)	C11—C12	1.4254 (13)
C4—C5	1.4241 (14)	C12—C13	1.4068 (13)
C5—N1	1.3025 (13)	C13—H13	0.93
C5—Cl1	1.7500 (10)	C14—O4	1.4301 (12)
C6—N1	1.3677 (12)	C14—H14A	0.96
C6—C12	1.4173 (14)	C14—H14B	0.96
C6—C7	1.4286 (14)	C14—H14C	0.96
C7—O2	1.3650 (14)

C2—C1—H1B	109.5	H8A—C8—H8B	109.5
C2—C1—H1A	109.5	O2—C8—H8C	109.5
H1B—C1—H1A	109.5	H8A—C8—H8C	109.5
C2—C1—H1C	109.5	H8B—C8—H8C	109.5
H1B—C1—H1C	109.5	C7—C9—C10	122.07 (9)
H1A—C1—H1C	109.5	C7—C9—H9	119
O1—C2—C1	106.85 (9)	C10—C9—H9	119
O1—C2—H2A	110.4	C11—C10—C9	120.01 (9)
C1—C2—H2A	110.4	C11—C10—H10	120
O1—C2—H2B	110.4	C9—C10—H10	120
C1—C2—H2B	110.4	O4—C11—C10	126.18 (8)
H2A—C2—H2B	108.6	O4—C11—C12	114.27 (8)
O3—C3—O1	123.25 (9)	C10—C11—C12	119.55 (9)
O3—C3—C4	126.28 (9)	C13—C12—C6	117.50 (8)
O1—C3—C4	110.46 (8)	C13—C12—C11	122.18 (9)
C13—C4—C5	116.02 (8)	C6—C12—C11	120.29 (8)
C13—C4—C3	119.42 (9)	C4—C13—C12	121.12 (9)
C5—C4—C3	124.56 (8)	C4—C13—H13	119.4
N1—C5—C4	125.27 (8)	C12—C13—H13	119.4
N1—C5—Cl1	114.12 (7)	O4—C14—H14A	109.5
C4—C5—Cl1	120.60 (7)	O4—C14—H14B	109.5
N1—C6—C12	121.71 (8)	H14A—C14—H14B	109.5
N1—C6—C7	118.96 (9)	O4—C14—H14C	109.5
C12—C6—C7	119.31 (8)	H14A—C14—H14C	109.5
O2—C7—C9	125.81 (9)	H14B—C14—H14C	109.5
O2—C7—C6	115.43 (9)	C5—N1—C6	118.38 (8)
C9—C7—C6	118.76 (9)	C3—O1—C2	115.86 (8)
O2—C8—H8A	109.5	C7—O2—C8	116.99 (8)
O2—C8—H8B	109.5	C11—O4—C14	116.88 (8)

O3—C3—C4—C13	−160.43 (10)	C7—C6—C12—C11	−0.20 (13)
O1—C3—C4—C13	18.58 (12)	O4—C11—C12—C13	1.56 (13)
O3—C3—C4—C5	18.55 (16)	C10—C11—C12—C13	−178.38 (9)
O1—C3—C4—C5	−162.43 (9)	O4—C11—C12—C6	179.62 (8)
C13—C4—C5—N1	−0.45 (14)	C10—C11—C12—C6	−0.32 (14)
C3—C4—C5—N1	−179.46 (9)	C5—C4—C13—C12	0.60 (13)
C13—C4—C5—Cl1	−178.93 (7)	C3—C4—C13—C12	179.67 (8)
C3—C4—C5—Cl1	2.06 (13)	C6—C12—C13—C4	−0.11 (13)
N1—C6—C7—O2	−1.04 (13)	C11—C12—C13—C4	178.00 (9)
C12—C6—C7—O2	−179.64 (8)	C4—C5—N1—C6	−0.23 (14)
N1—C6—C7—C9	178.96 (9)	Cl1—C5—N1—C6	178.33 (7)
C12—C6—C7—C9	0.36 (14)	C12—C6—N1—C5	0.77 (13)
O2—C7—C9—C10	179.98 (9)	C7—C6—N1—C5	−177.79 (9)
C6—C7—C9—C10	−0.02 (15)	O3—C3—O1—C2	3.72 (15)
C7—C9—C10—C11	−0.50 (15)	C4—C3—O1—C2	−175.33 (8)
C9—C10—C11—O4	−179.27 (9)	C1—C2—O1—C3	−172.08 (10)
C9—C10—C11—C12	0.66 (14)	C9—C7—O2—C8	−11.40 (15)
N1—C6—C12—C13	−0.60 (13)	C6—C7—O2—C8	168.60 (9)
C7—C6—C12—C13	177.95 (9)	C10—C11—O4—C14	7.48 (15)
N1—C6—C12—C11	−178.76 (9)	C12—C11—O4—C14	−172.46 (9)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10···O3ⁱ	0.93	2.56	3.482 (2)	173
C14—H14C···N1ⁱⁱ	0.96	2.61	3.476 (2)	150
C13—H13···O1	0.93	2.34	2.6713 (19)	101
C13—H13···O4	0.93	2.42	2.7366 (19)	100

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10···O3ⁱ	0.9300	2.5600	3.482 (2)	173.00
C14—H14C···N1ⁱⁱ	0.9600	2.6100	3.476 (2)	150.00

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

Acknowledgements

We are grateful to all personnel of the PHYSYNOR Laboratory, Universite Constantine 1, Algeria, for their assistance. Thanks are due to the MESRS (Ministére de l'Enseignement Supérieur et de la Recherche Scientifique - Algérie) for financial support.

References

Benzerka, S., Bouraiou, A., Bouacida, S., Roisnel, T., Bentchouala, C., Smati, F. & Belfaitah, A. (2012). Lett. Org. Chem. 9, 309–313. CrossRef CAS Google Scholar
Bouraiou, A., Bouacida, S., Bertrand, C., Roisnel, T. & Belfaitah, A. (2012). Acta Cryst. E68, o1701–o1702. CSD CrossRef CAS IUCr Journals Google Scholar
Brandenburg, K. & Berndt, M. (2001). DIAMOND. Crystal Impact, Bonn, Germany. Google Scholar
Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381–388. Web of Science CrossRef CAS IUCr Journals Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hayour, H., Bouraiou, A., Bouacida, S., Benzerka, S. & Belfaitah, A. (2014). Acta Cryst. E70, o195–o196. CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2002). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Valdez, D., Rodrigue-Morales, S., Hermandez-Copos, A., Hernandez-Luis, F., Ypez-Mulian, L., Tapia-Contreras, A. & Castillo, R. (2009). Bioorg. Med. Chem. 17, 1724–1730. Web of Science PubMed Google Scholar
Wang, X. J., Gong, D. L., Wang, J. D., Zhang, J., Liu, C. X. & Xiang, W. S. (2011). Bioorg. Med. Chem. Lett. 21, 2313–2315. Web of Science CrossRef CAS PubMed Google Scholar