Ethyl {4-[(1,5-dimethyl-2,4-dioxo-2,3,4,5-tetra­hydro-1H-1,5-benzo­diazepin-3-yl)meth­yl]-1,2,3-triazol-1-yl}acetate

Dardouri, R.; Kandri Rodi, Y.; Ladeira, S.; Essassi, E.M.; Ng, S.W.

doi:10.1107/S1600536810044120

organic compounds

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ISSN: 2056-9890

Volume 66| Part 11| November 2010| Page o3039

https://doi.org/10.1107/S1600536810044120

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Ethyl {4-[(1,5-dimethyl-2,4-dioxo-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-3-yl)methyl]-1,2,3-triazol-1-yl}acetate

Rachida Dardouri,^a Youssef Kandri Rodi,^a Sonia Ladeira,^b El Mokhtar Essassi ^a and Seik Weng Ng ^c ^*

^aLaboratoire de Chimie Organique Hétérocyclique, Pôle de Compétences Pharmacochimie, Université Mohammed V-Agdal, BP 1014 Avenue Ibn Batout, Rabat, Morocco, ^bService Commun Rayons-X, Laboratoire de Chimie de Coordination, 205 Route de Narbonne, Toulouse, France, and ^cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 27 October 2010; accepted 28 October 2010; online 31 October 2010)

In the title compound, C₁₈H₂₁N₅O₄, the diazepine ring adopts a boat conformation with the triazolylmethyl-bearing C atom as the prow and the C atoms at the ring junction as the stern.

Related literature

For the structure of 1,5-dimethyl-3-propargyl-1,5-benzodiazepine-2,4-dione, see: Dardouri et al. (2010 ).

Experimental

Crystal data

C₁₈H₂₁N₅O₄
M_r = 371.40
Monoclinic, P 2₁ /c
a = 8.5452 (2) Å
b = 15.9993 (5) Å
c = 13.9215 (4) Å
β = 106.853 (1)°
V = 1821.56 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.40 × 0.10 × 0.05 mm

Data collection

Bruker X8 APEXII diffractometer
15511 measured reflections
4129 independent reflections
2909 reflections with I > 2σ(I)
R_int = 0.037
Standard reflections: 0

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.124
S = 1.03
4129 reflections
247 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810044120/bt5398sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810044120/bt5398Isup2.hkl

checkCIF report

Comment top

1,5-Dimethyl-3-propargyl-1,5-benzodiazepine-2,4-dione, whose synthesis was reported recently (Dardouri et al., 2010), possess an acetylenic linkage that can be exploited for the synthesis of other 1,5-benzodiazepine-2,4-dione derivatives. In this study, the compound is reacted with ethyl 2-azidoacetate to yield the title compound (Scheme I, Fig. 1). The ester provides three nitrogen atoms necessary for the formation of the triazolyl ring.

Related literature top

For the structure of 1,5-dimethyl-3-propargyl-1,5-benzodiazepine-2,4-dione, see: Dardouri et al. (2010).

Experimental top

To a solution of 3-propargyl-1,5-dimethyl-1,5-benzodiazepine-2,4-dione (0.23 g,1 mmol) in a t-butyl alcohol/water mixture (1:2, 8 ml) was added copper sulfate pentahydrate (0.25 g,1 mmol), sodium ascorbate (0.29 g, 2 mmol) and ethyl 2-azidoacetate (0.64 g, 5 mmol). The mixture was stirred for two hours. Water (20 ml) was added and the organic compound was extracted with ethyl acetate (2 x 20 ml). The extracts were washed with brine and then dried over sodium sulfate. The compound was recrystallized from an n-hexane/ethyl acetate mixture to give colorless crystals.

Structure description top

For the structure of 1,5-dimethyl-3-propargyl-1,5-benzodiazepine-2,4-dione, see: Dardouri et al. (2010).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

Fig. 1. Anisotropic displacement ellipsoid plot (Barbour, 2001) of C₁₈H₂₁N₅O₄ at the 50% probability level; hydrogen atoms are drawn as arbitrary radius.

Ethyl {4-[(1,5-dimethyl-2,4-dioxo-2,3,4,5-tetrahydro-1H-1,5- benzodiazepin-3-yl)methyl]-1,2,3-triazol-1-yl}acetate top

Crystal data top

C₁₈H₂₁N₅O₄	F(000) = 784
M_r = 371.40	D_x = 1.354 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3798 reflections
a = 8.5452 (2) Å	θ = 2.5–26.4°
b = 15.9993 (5) Å	µ = 0.10 mm⁻¹
c = 13.9215 (4) Å	T = 293 K
β = 106.853 (1)°	Prism, colorless
V = 1821.56 (9) Å³	0.40 × 0.10 × 0.05 mm
Z = 4

Data collection top

Bruker X8 APEXII diffractometer	2909 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.037
Graphite monochromator	θ_max = 27.5°, θ_min = 2.8°
φ and ω scans	h = −10→10
15511 measured reflections	k = −20→20
4129 independent reflections	l = −18→18

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.124	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.052P)² + 0.6008P] where P = (F_o² + 2F_c²)/3
4129 reflections	(Δ/σ)_max = 0.001
247 parameters	Δρ_max = 0.30 e Å⁻³
0 restraints	Δρ_min = −0.31 e Å⁻³

Crystal data top

C₁₈H₂₁N₅O₄	V = 1821.56 (9) Å³
M_r = 371.40	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 8.5452 (2) Å	µ = 0.10 mm⁻¹
b = 15.9993 (5) Å	T = 293 K
c = 13.9215 (4) Å	0.40 × 0.10 × 0.05 mm
β = 106.853 (1)°

Data collection top

Bruker X8 APEXII diffractometer	2909 reflections with I > 2σ(I)
15511 measured reflections	R_int = 0.037
4129 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	0 restraints
wR(F²) = 0.124	H-atom parameters constrained
S = 1.03	Δρ_max = 0.30 e Å⁻³
4129 reflections	Δρ_min = −0.31 e Å⁻³
247 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.56199 (17)	0.18555 (8)	0.67466 (9)	0.0438 (3)
O2	0.81954 (18)	0.21921 (9)	0.49678 (10)	0.0505 (4)
O3	0.41269 (16)	0.12018 (9)	−0.04809 (9)	0.0440 (3)
O4	0.25337 (19)	0.10260 (14)	0.05096 (12)	0.0829 (7)
N1	0.78013 (17)	0.10102 (8)	0.73772 (10)	0.0285 (3)
N2	0.96549 (17)	0.11692 (10)	0.59493 (10)	0.0344 (4)
N3	0.52214 (17)	0.02996 (9)	0.35097 (10)	0.0314 (3)
N4	0.52862 (17)	0.02234 (9)	0.25819 (10)	0.0328 (3)
N5	0.52498 (17)	0.10028 (9)	0.22117 (10)	0.0291 (3)
C1	0.88147 (19)	0.03536 (10)	0.72159 (12)	0.0271 (4)
C2	0.8961 (2)	−0.03761 (11)	0.77820 (13)	0.0347 (4)
H2	0.8390	−0.0426	0.8255	0.042*
C3	0.9939 (2)	−0.10250 (12)	0.76516 (15)	0.0421 (5)
H3	1.0037	−0.1505	0.8042	0.050*
C4	1.0772 (2)	−0.09629 (13)	0.69423 (15)	0.0449 (5)
H4	1.1407	−0.1407	0.6840	0.054*
C5	1.0662 (2)	−0.02442 (13)	0.63862 (13)	0.0395 (5)
H5	1.1237	−0.0205	0.5914	0.047*
C6	0.97042 (19)	0.04275 (11)	0.65161 (12)	0.0300 (4)
C7	0.7764 (2)	0.11896 (12)	0.84068 (13)	0.0385 (4)
H7A	0.7659	0.1781	0.8486	0.058*
H7B	0.8758	0.0996	0.8875	0.058*
H7C	0.6849	0.0909	0.8531	0.058*
C8	0.6620 (2)	0.13566 (10)	0.66069 (12)	0.0301 (4)
C9	0.6685 (2)	0.11352 (10)	0.55590 (11)	0.0263 (3)
H9	0.6798	0.0528	0.5514	0.032*
C10	0.8228 (2)	0.15520 (11)	0.54480 (12)	0.0332 (4)
C11	1.1183 (2)	0.15061 (15)	0.58176 (15)	0.0499 (5)
H11A	1.1209	0.2101	0.5909	0.075*
H11B	1.1237	0.1378	0.5154	0.075*
H11C	1.2100	0.1258	0.6304	0.075*
C12	0.5152 (2)	0.14153 (11)	0.47517 (12)	0.0314 (4)
H12A	0.4195	0.1194	0.4904	0.038*
H12B	0.5083	0.2020	0.4755	0.038*
C13	0.51605 (19)	0.11257 (10)	0.37318 (12)	0.0274 (3)
C14	0.5173 (2)	0.15758 (11)	0.29023 (12)	0.0295 (4)
H14	0.5136	0.2154	0.2830	0.035*
C15	0.5444 (2)	0.11311 (12)	0.12218 (12)	0.0339 (4)
H15A	0.6163	0.0703	0.1096	0.041*
H15B	0.5963	0.1668	0.1207	0.041*
C16	0.3849 (2)	0.11069 (11)	0.03967 (13)	0.0366 (4)
C17	0.2699 (3)	0.11868 (14)	−0.13697 (14)	0.0487 (5)
H17A	0.1960	0.0748	−0.1294	0.058*
H17B	0.3051	0.1058	−0.1956	0.058*
C18	0.1815 (2)	0.19999 (12)	−0.15270 (14)	0.0435 (5)
H18A	0.0900	0.1969	−0.2121	0.065*
H18B	0.2542	0.2436	−0.1603	0.065*
H18C	0.1431	0.2120	−0.0958	0.065*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0564 (9)	0.0414 (7)	0.0342 (7)	0.0164 (6)	0.0141 (6)	−0.0056 (6)
O2	0.0584 (9)	0.0477 (8)	0.0410 (8)	−0.0153 (7)	0.0074 (7)	0.0153 (6)
O3	0.0389 (7)	0.0690 (9)	0.0205 (6)	0.0060 (6)	0.0030 (5)	−0.0024 (6)
O4	0.0371 (9)	0.1597 (19)	0.0459 (10)	−0.0232 (10)	0.0022 (7)	0.0413 (11)
N1	0.0337 (8)	0.0327 (7)	0.0201 (7)	−0.0024 (6)	0.0091 (6)	−0.0031 (5)
N2	0.0301 (8)	0.0491 (9)	0.0242 (7)	−0.0106 (7)	0.0080 (6)	0.0014 (6)
N3	0.0320 (8)	0.0344 (8)	0.0264 (7)	−0.0013 (6)	0.0063 (6)	0.0015 (6)
N4	0.0352 (8)	0.0332 (8)	0.0274 (7)	−0.0031 (6)	0.0050 (6)	0.0005 (6)
N5	0.0287 (7)	0.0341 (8)	0.0223 (7)	−0.0019 (6)	0.0040 (5)	0.0016 (6)
C1	0.0246 (8)	0.0334 (8)	0.0217 (8)	−0.0037 (7)	0.0043 (6)	−0.0038 (6)
C2	0.0307 (9)	0.0398 (10)	0.0312 (9)	−0.0051 (7)	0.0053 (7)	0.0024 (7)
C3	0.0365 (10)	0.0369 (10)	0.0446 (11)	0.0011 (8)	−0.0013 (8)	0.0032 (8)
C4	0.0312 (10)	0.0519 (12)	0.0437 (11)	0.0111 (8)	−0.0017 (8)	−0.0094 (9)
C5	0.0256 (9)	0.0631 (13)	0.0273 (9)	0.0038 (8)	0.0035 (7)	−0.0092 (9)
C6	0.0239 (8)	0.0429 (10)	0.0203 (8)	−0.0053 (7)	0.0018 (6)	−0.0034 (7)
C7	0.0472 (11)	0.0469 (11)	0.0227 (9)	−0.0019 (9)	0.0119 (8)	−0.0072 (8)
C8	0.0376 (10)	0.0269 (8)	0.0262 (8)	−0.0007 (7)	0.0098 (7)	−0.0017 (6)
C9	0.0310 (9)	0.0263 (8)	0.0214 (8)	0.0005 (7)	0.0069 (6)	−0.0008 (6)
C10	0.0395 (10)	0.0387 (9)	0.0204 (8)	−0.0080 (8)	0.0069 (7)	−0.0015 (7)
C11	0.0375 (11)	0.0799 (15)	0.0324 (10)	−0.0239 (10)	0.0104 (8)	0.0009 (10)
C12	0.0314 (9)	0.0361 (9)	0.0259 (8)	0.0072 (7)	0.0072 (7)	0.0018 (7)
C13	0.0229 (8)	0.0319 (8)	0.0255 (8)	0.0013 (6)	0.0042 (6)	0.0024 (7)
C14	0.0299 (9)	0.0296 (8)	0.0272 (8)	0.0010 (7)	0.0051 (7)	0.0016 (7)
C15	0.0329 (9)	0.0448 (10)	0.0225 (8)	−0.0031 (8)	0.0055 (7)	0.0001 (7)
C16	0.0348 (10)	0.0418 (10)	0.0293 (9)	−0.0072 (8)	0.0033 (7)	0.0055 (7)
C17	0.0509 (12)	0.0617 (13)	0.0231 (9)	0.0071 (10)	−0.0056 (8)	−0.0067 (9)
C18	0.0438 (11)	0.0441 (11)	0.0352 (10)	−0.0068 (9)	−0.0002 (8)	0.0007 (8)

Geometric parameters (Å, º) top

O1—C8	1.225 (2)	C5—H5	0.9300
O2—C10	1.219 (2)	C7—H7A	0.9600
O3—C16	1.319 (2)	C7—H7B	0.9600
O3—C17	1.464 (2)	C7—H7C	0.9600
O4—C16	1.186 (2)	C8—C9	1.518 (2)
N1—C8	1.360 (2)	C9—C12	1.525 (2)
N1—C1	1.420 (2)	C9—C10	1.524 (2)
N1—C7	1.471 (2)	C9—H9	0.9800
N2—C10	1.362 (2)	C11—H11A	0.9600
N2—C6	1.419 (2)	C11—H11B	0.9600
N2—C11	1.473 (2)	C11—H11C	0.9600
N3—N4	1.3145 (19)	C12—C13	1.495 (2)
N3—C13	1.362 (2)	C12—H12A	0.9700
N4—N5	1.3462 (19)	C12—H12B	0.9700
N5—C14	1.344 (2)	C13—C14	1.364 (2)
N5—C15	1.450 (2)	C14—H14	0.9300
C1—C2	1.394 (2)	C15—C16	1.507 (2)
C1—C6	1.404 (2)	C15—H15A	0.9700
C2—C3	1.377 (3)	C15—H15B	0.9700
C2—H2	0.9300	C17—C18	1.489 (3)
C3—C4	1.378 (3)	C17—H17A	0.9700
C3—H3	0.9300	C17—H17B	0.9700
C4—C5	1.374 (3)	C18—H18A	0.9600
C4—H4	0.9300	C18—H18B	0.9600
C5—C6	1.394 (3)	C18—H18C	0.9600

C16—O3—C17	116.81 (15)	C10—C9—H9	108.9
C8—N1—C1	121.62 (13)	O2—C10—N2	122.21 (16)
C8—N1—C7	117.89 (14)	O2—C10—C9	122.71 (16)
C1—N1—C7	119.01 (14)	N2—C10—C9	115.05 (15)
C10—N2—C6	122.59 (14)	N2—C11—H11A	109.5
C10—N2—C11	117.80 (16)	N2—C11—H11B	109.5
C6—N2—C11	119.40 (15)	H11A—C11—H11B	109.5
N4—N3—C13	109.17 (13)	N2—C11—H11C	109.5
N3—N4—N5	106.71 (13)	H11A—C11—H11C	109.5
C14—N5—N4	111.01 (13)	H11B—C11—H11C	109.5
C14—N5—C15	128.78 (14)	C13—C12—C9	111.66 (13)
N4—N5—C15	119.93 (14)	C13—C12—H12A	109.3
C2—C1—C6	119.01 (15)	C9—C12—H12A	109.3
C2—C1—N1	119.29 (15)	C13—C12—H12B	109.3
C6—C1—N1	121.68 (15)	C9—C12—H12B	109.3
C3—C2—C1	121.03 (17)	H12A—C12—H12B	107.9
C3—C2—H2	119.5	C14—C13—N3	108.06 (15)
C1—C2—H2	119.5	C14—C13—C12	130.07 (15)
C2—C3—C4	119.94 (18)	N3—C13—C12	121.82 (14)
C2—C3—H3	120.0	N5—C14—C13	105.05 (15)
C4—C3—H3	120.0	N5—C14—H14	127.5
C5—C4—C3	119.93 (18)	C13—C14—H14	127.5
C5—C4—H4	120.0	N5—C15—C16	113.16 (14)
C3—C4—H4	120.0	N5—C15—H15A	108.9
C4—C5—C6	121.26 (17)	C16—C15—H15A	108.9
C4—C5—H5	119.4	N5—C15—H15B	108.9
C6—C5—H5	119.4	C16—C15—H15B	108.9
C5—C6—C1	118.78 (16)	H15A—C15—H15B	107.8
C5—C6—N2	119.78 (15)	O4—C16—O3	124.56 (17)
C1—C6—N2	121.44 (15)	O4—C16—C15	125.75 (17)
N1—C7—H7A	109.5	O3—C16—C15	109.69 (15)
N1—C7—H7B	109.5	O3—C17—C18	111.90 (16)
H7A—C7—H7B	109.5	O3—C17—H17A	109.2
N1—C7—H7C	109.5	C18—C17—H17A	109.2
H7A—C7—H7C	109.5	O3—C17—H17B	109.2
H7B—C7—H7C	109.5	C18—C17—H17B	109.2
O1—C8—N1	122.20 (15)	H17A—C17—H17B	107.9
O1—C8—C9	121.75 (15)	C17—C18—H18A	109.5
N1—C8—C9	115.91 (14)	C17—C18—H18B	109.5
C8—C9—C12	112.12 (13)	H18A—C18—H18B	109.5
C8—C9—C10	105.62 (13)	C17—C18—H18C	109.5
C12—C9—C10	112.32 (14)	H18A—C18—H18C	109.5
C8—C9—H9	108.9	H18B—C18—H18C	109.5
C12—C9—H9	108.9

C13—N3—N4—N5	−0.60 (17)	O1—C8—C9—C10	107.96 (18)
N3—N4—N5—C14	0.41 (17)	N1—C8—C9—C10	−67.92 (18)
N3—N4—N5—C15	174.79 (13)	C6—N2—C10—O2	179.53 (16)
C8—N1—C1—C2	−127.81 (17)	C11—N2—C10—O2	−5.9 (3)
C7—N1—C1—C2	38.0 (2)	C6—N2—C10—C9	1.3 (2)
C8—N1—C1—C6	53.7 (2)	C11—N2—C10—C9	175.88 (15)
C7—N1—C1—C6	−140.50 (16)	C8—C9—C10—O2	−103.15 (18)
C6—C1—C2—C3	−1.1 (2)	C12—C9—C10—O2	19.4 (2)
N1—C1—C2—C3	−179.65 (15)	C8—C9—C10—N2	75.09 (17)
C1—C2—C3—C4	−0.9 (3)	C12—C9—C10—N2	−162.40 (14)
C2—C3—C4—C5	1.8 (3)	C8—C9—C12—C13	−174.76 (14)
C3—C4—C5—C6	−0.7 (3)	C10—C9—C12—C13	66.48 (18)
C4—C5—C6—C1	−1.3 (2)	N4—N3—C13—C14	0.58 (18)
C4—C5—C6—N2	178.22 (15)	N4—N3—C13—C12	−177.28 (14)
C2—C1—C6—C5	2.2 (2)	C9—C12—C13—C14	−117.25 (19)
N1—C1—C6—C5	−179.29 (15)	C9—C12—C13—N3	60.1 (2)
C2—C1—C6—N2	−177.35 (14)	N4—N5—C14—C13	−0.06 (18)
N1—C1—C6—N2	1.2 (2)	C15—N5—C14—C13	−173.80 (15)
C10—N2—C6—C5	131.51 (17)	N3—C13—C14—N5	−0.31 (18)
C11—N2—C6—C5	−43.0 (2)	C12—C13—C14—N5	177.32 (16)
C10—N2—C6—C1	−49.0 (2)	C14—N5—C15—C16	−97.7 (2)
C11—N2—C6—C1	136.53 (17)	N4—N5—C15—C16	89.08 (19)
C1—N1—C8—O1	171.63 (16)	C17—O3—C16—O4	−1.3 (3)
C7—N1—C8—O1	5.6 (2)	C17—O3—C16—C15	179.53 (16)
C1—N1—C8—C9	−12.5 (2)	N5—C15—C16—O4	2.8 (3)
C7—N1—C8—C9	−178.49 (14)	N5—C15—C16—O3	−178.05 (15)
O1—C8—C9—C12	−14.7 (2)	C16—O3—C17—C18	79.5 (2)
N1—C8—C9—C12	169.44 (14)

Experimental details

Crystal data
Chemical formula	C₁₈H₂₁N₅O₄
M_r	371.40
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	8.5452 (2), 15.9993 (5), 13.9215 (4)
β (°)	106.853 (1)
V (Å³)	1821.56 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.40 × 0.10 × 0.05

Data collection
Diffractometer	Bruker X8 APEXII
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	15511, 4129, 2909
R_int	0.037
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.124, 1.03
No. of reflections	4129
No. of parameters	247
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.31

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

Acknowledgements

We thank Université Mohammed V-Agdal and the University of Malaya for supporting this study.

References

Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dardouri, R., Ouazzani Chahdi, F., Saffon, N., Essassi, E. M. & Ng, S. W. (2010). Acta Cryst. E66, o1797. 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
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

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