1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one

Dahmani, S.; Kandri Rodi, Y.; Capet, F.; Essassi, E.M.; Ng, S.W.

doi:10.1107/S1600536810007713

organic compounds

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ISSN: 2056-9890

Volume 66| Part 4| April 2010| Page o754

doi:10.1107/S1600536810007713

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1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one

S. Dahmani,^a Y. Kandri Rodi,^a F. Capet,^b El Mokhtar Essassi ^c and Seik Weng Ng ^d ^*

^aLaboratoire de Chimie Organique Appliquée, Faculté des Sciences et Techniques, Université Sidi Mohamed Ben Abdallah, Fés, Morocco, ^bUnité de Catalyse et de Chimie du Solide, Ecole Nationale Supérieure de Chimie de Lille, Lille, France, ^cLaboratoire de Chimie Organique Hétérocyclique, Pôle de Compétences Pharmacochimie, Université Mohammed V-Agdal, BP 1014 Avenue Ibn Batout, Rabat, Morocco, and ^dDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 24 February 2010; accepted 1 March 2010; online 6 March 2010)

The imidazopyridine fused-ring in the title compound, C₂₀H₁₆BrN₃O, is planar (r.m.s. deviation = 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1)° with respect to this ring.

Related literature

For the medicinal applications of 1,3-dihydro-imidazo[4,5-b]pyridin-2-ones, see: Barraclough et al. (1990 ); Cundy et al. (1997 ); Desarro et al. (1994 ); Liu et al. (2008 ); Mader et al. (2008 ); Zaki & Proença (2007 ). For the product of the reaction of propargyl bromide with 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in DMF at room and high temperatures, see: Dahmani et al. (2010a ,b ).

Experimental

Crystal data

C₂₀H₁₆BrN₃O
M_r = 394.27
Monoclinic, P 2₁ /c
a = 9.1627 (1) Å
b = 25.5071 (3) Å
c = 8.0629 (1) Å
β = 115.571 (1)°
V = 1699.84 (3) Å³
Z = 4
Mo Kα radiation
μ = 2.43 mm⁻¹
T = 293 K
0.42 × 0.18 × 0.13 mm

Data collection

Bruker X8 APEX2 diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.428, T_max = 0.743
38010 measured reflections
3903 independent reflections
2967 reflections with I > 2σ(I)
R_int = 0.036

Refinement

R[F² > 2σ(F²)] = 0.041
wR(F²) = 0.138
S = 1.07
3903 reflections
226 parameters
H-atom parameters constrained
Δρ_max = 0.84 e Å⁻³
Δρ_min = −0.90 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: 10.1107/S1600536810007713/hg2651sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810007713/hg2651Isup2.hkl

checkCIF report

Comment top

Imidazo[4,5-b]pyridines are precursors for the synthesis of a variety of medicinal agents as compounds having the imidazo[4,5-b]pyridine fused-ring system possess a broad range of pharmacological activities (Barraclough et al., 1990; Cundy et al., 1997; Desarro et al., 1994; Liu et al., 2008; Mader et al., 2008; Zaki & Proença, 2007).

The present study represents the synthesis of the substituted an imidazo[4,5-b]pyridin-2-one derivative by the direct action of benzyl chloride on 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in boiling DMF.

The imidazopyridine fused-ring in C₂₀H₁₆BrN₃O (Scheme I, Fig. 1) is planar (r.m.s. deviation 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1) ° with respect to this ring.

The temperature of the reaction, in the case of propargyl bromide, governs the nature of the product (Dahmani et al., 2010a, 2010b).

Related literature top

For the medicinal applications of 1,3-dihydro-imidazo[4,5-b]pyridin-2-ones, see: Barraclough et al. (1990); Cundy et al. (1997); Desarro et al. (1994); Liu et al. (2008); Mader et al. (2008); Zaki & Proença (2007). For the product of the reaction of propargyl bromide with 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in DMF at room and high temperatures, see: Dahmani et al. (2010a,b).

Experimental top

To a mixture of 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one (1 mmol), potassium carbonate (4 mmol) and benzyltributylammonium chloride (0.1 mmol) in DMF was added benzyl chloride (2.5 mmol). The mixture was stirred for 48 hours. After completion of reaction (monitored by TLC), the inorganic salt was filtered and the solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel with ethyl acetate/hexane (1/1) as eluent. Colorless crystals were isolated when the solvent was allowed to evaporate.

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. Thermal ellipsoid plot (Barbour, 2001) of C₂₀H₁₆BrN₃O at the 50% probability level; hydrogen atoms are drawn as arbitrary radius.

1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one top

Crystal data top

C₂₀H₁₆BrN₃O	F(000) = 800
M_r = 394.27	D_x = 1.541 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9890 reflections
a = 9.1627 (1) Å	θ = 2.5–25.0°
b = 25.5071 (3) Å	µ = 2.43 mm⁻¹
c = 8.0629 (1) Å	T = 293 K
β = 115.571 (1)°	Prism, colorless
V = 1699.84 (3) Å³	0.42 × 0.18 × 0.13 mm
Z = 4

Data collection top

Bruker X8 APEX2 diffractometer	3903 independent reflections
Radiation source: fine-focus sealed tube	2967 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.036
ϕ and ω scans	θ_max = 27.5°, θ_min = 1.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −11→11
T_min = 0.428, T_max = 0.743	k = −33→33
38010 measured reflections	l = −9→10

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.138	H-atom parameters constrained
S = 1.07	w = 1/[σ²(F_o²) + (0.0688P)² + 1.1691P] where P = (F_o² + 2F_c²)/3
3903 reflections	(Δ/σ)_max = 0.001
226 parameters	Δρ_max = 0.84 e Å⁻³
0 restraints	Δρ_min = −0.90 e Å⁻³

Crystal data top

C₂₀H₁₆BrN₃O	V = 1699.84 (3) Å³
M_r = 394.27	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 9.1627 (1) Å	µ = 2.43 mm⁻¹
b = 25.5071 (3) Å	T = 293 K
c = 8.0629 (1) Å	0.42 × 0.18 × 0.13 mm
β = 115.571 (1)°

Data collection top

Bruker X8 APEX2 diffractometer	3903 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2967 reflections with I > 2σ(I)
T_min = 0.428, T_max = 0.743	R_int = 0.036
38010 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	0 restraints
wR(F²) = 0.138	H-atom parameters constrained
S = 1.07	Δρ_max = 0.84 e Å⁻³
3903 reflections	Δρ_min = −0.90 e Å⁻³
226 parameters

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

	x	y	z	U_iso*/U_eq
Br1	0.75465 (4)	0.225888 (14)	0.48173 (6)	0.07328 (18)
O1	0.2072 (3)	0.45942 (8)	0.3332 (3)	0.0570 (5)
N1	0.3210 (3)	0.28134 (9)	0.4493 (3)	0.0480 (6)
N2	0.2208 (3)	0.36984 (9)	0.3920 (3)	0.0399 (5)
N3	0.4318 (3)	0.40833 (8)	0.3767 (3)	0.0398 (5)
C1	0.4498 (4)	0.25184 (12)	0.4685 (4)	0.0515 (7)
H1	0.4465	0.2160	0.4879	0.062*
C2	0.5858 (4)	0.27231 (11)	0.4606 (4)	0.0473 (7)
C3	0.6008 (3)	0.32553 (11)	0.4321 (4)	0.0428 (6)
H3	0.6926	0.3396	0.4275	0.051*
C4	0.4695 (3)	0.35553 (10)	0.4115 (3)	0.0366 (5)
C5	0.3351 (3)	0.33129 (10)	0.4207 (3)	0.0366 (5)
C6	0.2777 (3)	0.41774 (10)	0.3635 (4)	0.0401 (6)
C7	0.0593 (3)	0.36191 (13)	0.3822 (4)	0.0482 (7)
H7A	0.0226	0.3269	0.3356	0.058*
H7B	−0.0145	0.3867	0.2952	0.058*
C8	0.0513 (3)	0.36830 (10)	0.5637 (4)	0.0376 (5)
C9	0.0052 (3)	0.41597 (11)	0.6102 (4)	0.0448 (6)
H9	−0.0162	0.4444	0.5310	0.054*
C10	−0.0090 (4)	0.42129 (13)	0.7723 (4)	0.0530 (7)
H10	−0.0399	0.4533	0.8023	0.064*
C11	0.0223 (4)	0.37940 (15)	0.8905 (4)	0.0572 (8)
H11	0.0105	0.3829	0.9989	0.069*
C12	0.0711 (4)	0.33231 (14)	0.8480 (5)	0.0581 (8)
H12	0.0946	0.3042	0.9291	0.070*
C13	0.0854 (3)	0.32658 (12)	0.6849 (4)	0.0490 (7)
H13	0.1180	0.2946	0.6565	0.059*
C14	0.5321 (4)	0.44829 (11)	0.3487 (4)	0.0431 (6)
H14A	0.6349	0.4498	0.4570	0.052*
H14B	0.4797	0.4821	0.3362	0.052*
C15	0.5641 (3)	0.43916 (9)	0.1821 (3)	0.0349 (5)
C16	0.6900 (3)	0.46603 (11)	0.1695 (4)	0.0437 (6)
H16	0.7526	0.4889	0.2630	0.052*
C17	0.7240 (4)	0.45935 (14)	0.0203 (4)	0.0549 (8)
H17	0.8092	0.4777	0.0137	0.066*
C18	0.6319 (4)	0.42548 (13)	−0.1197 (4)	0.0533 (7)
H18	0.6559	0.4204	−0.2194	0.064*
C19	0.5046 (4)	0.39937 (12)	−0.1105 (4)	0.0498 (7)
H19	0.4411	0.3770	−0.2055	0.060*
C20	0.4702 (3)	0.40613 (11)	0.0401 (4)	0.0445 (6)
H20	0.3836	0.3884	0.0453	0.053*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0600 (2)	0.0554 (2)	0.0961 (3)	0.01808 (15)	0.0259 (2)	0.00089 (17)
O1	0.0630 (13)	0.0486 (12)	0.0681 (14)	0.0147 (10)	0.0364 (11)	0.0062 (10)
N1	0.0528 (14)	0.0437 (13)	0.0526 (14)	−0.0072 (10)	0.0274 (12)	0.0003 (10)
N2	0.0410 (11)	0.0455 (12)	0.0394 (12)	−0.0017 (9)	0.0233 (10)	−0.0020 (9)
N3	0.0454 (12)	0.0371 (11)	0.0455 (12)	−0.0015 (9)	0.0277 (10)	0.0009 (9)
C1	0.0595 (18)	0.0372 (15)	0.0584 (18)	−0.0029 (13)	0.0261 (15)	0.0018 (13)
C2	0.0459 (15)	0.0424 (15)	0.0494 (16)	0.0071 (12)	0.0166 (13)	−0.0007 (12)
C3	0.0398 (13)	0.0436 (14)	0.0478 (15)	0.0001 (11)	0.0214 (12)	−0.0026 (12)
C4	0.0424 (13)	0.0371 (12)	0.0336 (12)	−0.0029 (10)	0.0194 (11)	−0.0028 (10)
C5	0.0392 (13)	0.0400 (13)	0.0336 (12)	−0.0026 (10)	0.0186 (10)	−0.0031 (10)
C6	0.0482 (15)	0.0438 (14)	0.0346 (13)	0.0014 (12)	0.0239 (11)	−0.0020 (11)
C7	0.0359 (13)	0.0663 (19)	0.0426 (15)	−0.0056 (12)	0.0172 (12)	−0.0081 (13)
C8	0.0291 (11)	0.0463 (14)	0.0404 (13)	−0.0053 (10)	0.0177 (10)	−0.0025 (11)
C9	0.0402 (14)	0.0445 (15)	0.0506 (16)	0.0020 (11)	0.0204 (12)	0.0050 (12)
C10	0.0482 (16)	0.0594 (18)	0.0570 (18)	0.0009 (14)	0.0279 (14)	−0.0135 (15)
C11	0.0468 (16)	0.090 (2)	0.0415 (16)	−0.0001 (16)	0.0251 (13)	−0.0038 (16)
C12	0.0531 (18)	0.069 (2)	0.0566 (19)	0.0009 (15)	0.0276 (15)	0.0177 (16)
C13	0.0460 (15)	0.0441 (15)	0.0637 (18)	0.0007 (12)	0.0302 (14)	0.0014 (13)
C14	0.0544 (16)	0.0379 (13)	0.0447 (15)	−0.0103 (12)	0.0287 (13)	−0.0057 (11)
C15	0.0382 (12)	0.0309 (12)	0.0383 (13)	0.0023 (10)	0.0190 (11)	0.0031 (10)
C16	0.0412 (14)	0.0442 (15)	0.0437 (15)	−0.0059 (11)	0.0166 (12)	0.0001 (11)
C17	0.0486 (17)	0.066 (2)	0.0605 (19)	−0.0051 (14)	0.0338 (16)	0.0068 (15)
C18	0.0600 (18)	0.0642 (19)	0.0467 (16)	0.0081 (15)	0.0333 (15)	0.0053 (14)
C19	0.0571 (17)	0.0519 (16)	0.0401 (15)	−0.0015 (13)	0.0206 (13)	−0.0074 (12)
C20	0.0460 (15)	0.0461 (15)	0.0463 (15)	−0.0085 (12)	0.0245 (13)	−0.0048 (12)

Geometric parameters (Å, º) top

Br1—C2	1.897 (3)	C9—H9	0.9300
O1—C6	1.213 (3)	C10—C11	1.377 (5)
N1—C5	1.311 (3)	C10—H10	0.9300
N1—C1	1.351 (4)	C11—C12	1.376 (5)
N2—C5	1.382 (3)	C11—H11	0.9300
N2—C6	1.386 (3)	C12—C13	1.384 (5)
N2—C7	1.462 (3)	C12—H12	0.9300
N3—C4	1.389 (3)	C13—H13	0.9300
N3—C6	1.391 (3)	C14—C15	1.512 (4)
N3—C14	1.453 (3)	C14—H14A	0.9700
C1—C2	1.377 (4)	C14—H14B	0.9700
C1—H1	0.9300	C15—C20	1.382 (4)
C2—C3	1.393 (4)	C15—C16	1.383 (4)
C3—C4	1.374 (4)	C16—C17	1.377 (4)
C3—H3	0.9300	C16—H16	0.9300
C4—C5	1.408 (4)	C17—C18	1.382 (5)
C7—C8	1.505 (4)	C17—H17	0.9300
C7—H7A	0.9700	C18—C19	1.372 (5)
C7—H7B	0.9700	C18—H18	0.9300
C8—C13	1.386 (4)	C19—C20	1.391 (4)
C8—C9	1.390 (4)	C19—H19	0.9300
C9—C10	1.376 (4)	C20—H20	0.9300

C5—N1—C1	114.4 (2)	C9—C10—C11	120.3 (3)
C5—N2—C6	110.0 (2)	C9—C10—H10	119.9
C5—N2—C7	126.0 (2)	C11—C10—H10	119.9
C6—N2—C7	123.9 (2)	C12—C11—C10	119.9 (3)
C4—N3—C6	109.8 (2)	C12—C11—H11	120.1
C4—N3—C14	126.4 (2)	C10—C11—H11	120.1
C6—N3—C14	123.8 (2)	C11—C12—C13	120.2 (3)
N1—C1—C2	123.1 (3)	C11—C12—H12	119.9
N1—C1—H1	118.4	C13—C12—H12	119.9
C2—C1—H1	118.4	C12—C13—C8	120.2 (3)
C1—C2—C3	122.2 (3)	C12—C13—H13	119.9
C1—C2—Br1	118.6 (2)	C8—C13—H13	119.9
C3—C2—Br1	119.2 (2)	N3—C14—C15	114.1 (2)
C4—C3—C2	114.8 (3)	N3—C14—H14A	108.7
C4—C3—H3	122.6	C15—C14—H14A	108.7
C2—C3—H3	122.6	N3—C14—H14B	108.7
C3—C4—N3	133.9 (2)	C15—C14—H14B	108.7
C3—C4—C5	119.3 (2)	H14A—C14—H14B	107.6
N3—C4—C5	106.9 (2)	C20—C15—C16	118.8 (2)
N1—C5—N2	126.6 (2)	C20—C15—C14	122.7 (2)
N1—C5—C4	126.2 (3)	C16—C15—C14	118.5 (2)
N2—C5—C4	107.2 (2)	C17—C16—C15	120.9 (3)
O1—C6—N2	126.9 (3)	C17—C16—H16	119.6
O1—C6—N3	127.0 (3)	C15—C16—H16	119.6
N2—C6—N3	106.1 (2)	C16—C17—C18	120.1 (3)
N2—C7—C8	113.9 (2)	C16—C17—H17	120.0
N2—C7—H7A	108.8	C18—C17—H17	120.0
C8—C7—H7A	108.8	C19—C18—C17	119.6 (3)
N2—C7—H7B	108.8	C19—C18—H18	120.2
C8—C7—H7B	108.8	C17—C18—H18	120.2
H7A—C7—H7B	107.7	C18—C19—C20	120.3 (3)
C13—C8—C9	118.9 (2)	C18—C19—H19	119.8
C13—C8—C7	120.7 (3)	C20—C19—H19	119.8
C9—C8—C7	120.3 (3)	C15—C20—C19	120.3 (3)
C10—C9—C8	120.4 (3)	C15—C20—H20	119.9
C10—C9—H9	119.8	C19—C20—H20	119.9
C8—C9—H9	119.8

C5—N1—C1—C2	0.6 (4)	C4—N3—C6—N2	0.4 (3)
N1—C1—C2—C3	0.0 (5)	C14—N3—C6—N2	177.7 (2)
N1—C1—C2—Br1	−178.0 (2)	C5—N2—C7—C8	92.2 (3)
C1—C2—C3—C4	−0.4 (4)	C6—N2—C7—C8	−91.5 (3)
Br1—C2—C3—C4	177.6 (2)	N2—C7—C8—C13	−86.0 (3)
C2—C3—C4—N3	−178.0 (3)	N2—C7—C8—C9	95.7 (3)
C2—C3—C4—C5	0.1 (4)	C13—C8—C9—C10	−1.1 (4)
C6—N3—C4—C3	178.2 (3)	C7—C8—C9—C10	177.2 (3)
C14—N3—C4—C3	0.9 (5)	C8—C9—C10—C11	0.0 (4)
C6—N3—C4—C5	−0.1 (3)	C9—C10—C11—C12	1.3 (5)
C14—N3—C4—C5	−177.4 (2)	C10—C11—C12—C13	−1.4 (5)
C1—N1—C5—N2	178.3 (3)	C11—C12—C13—C8	0.3 (5)
C1—N1—C5—C4	−1.0 (4)	C9—C8—C13—C12	1.0 (4)
C6—N2—C5—N1	−178.9 (3)	C7—C8—C13—C12	−177.3 (3)
C7—N2—C5—N1	−2.1 (4)	C4—N3—C14—C15	62.6 (4)
C6—N2—C5—C4	0.5 (3)	C6—N3—C14—C15	−114.3 (3)
C7—N2—C5—C4	177.3 (2)	N3—C14—C15—C20	18.6 (4)
C3—C4—C5—N1	0.6 (4)	N3—C14—C15—C16	−163.1 (2)
N3—C4—C5—N1	179.2 (3)	C20—C15—C16—C17	−1.3 (4)
C3—C4—C5—N2	−178.8 (2)	C14—C15—C16—C17	−179.7 (3)
N3—C4—C5—N2	−0.2 (3)	C15—C16—C17—C18	0.1 (5)
C5—N2—C6—O1	179.4 (3)	C16—C17—C18—C19	1.2 (5)
C7—N2—C6—O1	2.6 (4)	C17—C18—C19—C20	−1.2 (5)
C5—N2—C6—N3	−0.5 (3)	C16—C15—C20—C19	1.4 (4)
C7—N2—C6—N3	−177.4 (2)	C14—C15—C20—C19	179.7 (3)
C4—N3—C6—O1	−179.6 (3)	C18—C19—C20—C15	−0.1 (5)
C14—N3—C6—O1	−2.2 (4)

Experimental details

Crystal data
Chemical formula	C₂₀H₁₆BrN₃O
M_r	394.27
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	9.1627 (1), 25.5071 (3), 8.0629 (1)
β (°)	115.571 (1)
V (Å³)	1699.84 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	2.43
Crystal size (mm)	0.42 × 0.18 × 0.13

Data collection
Diffractometer	Bruker X8 APEX2 diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.428, 0.743
No. of measured, independent and observed [I > 2σ(I)] reflections	38010, 3903, 2967
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.138, 1.07
No. of reflections	3903
No. of parameters	226
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.84, −0.90

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 Sidi Mohammed Ben Abdallah, Université Mohammed V-Agdal and the University of Malaya for supporting this study.

References

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