2-Hydr­oxy-10-phenacyl­pyrrolo[2,1-c][1,4]benzodiazepine-5,11-dione

Ourahou, S.; Chammache, M.; Zouihri, H.; Essassi, E.M.; Ng, S.W.

doi:10.1107/S1600536810006902

organic compounds

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ISSN: 2056-9890

Volume 66| Part 4| April 2010| Page o732

doi:10.1107/S1600536810006902

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2-Hydroxy-10-phenacylpyrrolo[2,1-c][1,4]benzodiazepine-5,11-dione

S. Ourahou,^a M. Chammache,^a H. Zouihri,^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, ^bCNRST, Division of UATRS Angle Allal Fassi/FAR, BP 8027 Hay Riad, 10000 Rabat, Morocco, and ^cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: seikweng@um.edu.my

(Received 21 February 2010; accepted 23 February 2010; online 3 March 2010)

The title compound, C₂₀H₁₈N₂O₄, consists of a benzodiazepinedione system fused to a pyrrole system. The seven-membered ring adopts a boat-shaped conformation (with the methine C atom as the prow); the five-membered ring adopts an enveloped-shaped conformation (with the hydroxy-bearing C atom as the flap). In the crystal, the hydroxy group is hydrogen bonded to the carbonyl O atom of an adjacent molecule, generating a zigzag chain.

Related literature

Pyrrolo[2,1-c][1,4]benzodiazepines are potent antibiotics produced by Streptomyces species; see: Cargill et al. (1974 ). For the design of DNA inter-strand cross-linkingand conjugate agents to enhance the sequence selectivity and selectivity for tumor cells, see: Gregson et al. (2004 ).

Experimental

Crystal data

C₂₀H₁₈N₂O₄
M_r = 350.36
Orthorhombic, P 2₁ 2₁ 2₁
a = 8.8337 (2) Å
b = 9.9476 (2) Å
c = 18.9295 (4) Å
V = 1663.41 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.3 × 0.3 × 0.3 mm

Data collection

Bruker APEXII diffractometer
12798 measured reflections
2189 independent reflections
1967 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.118
S = 1.15
2189 reflections
239 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O1ⁱ	0.84 (1)	2.02 (2)	2.810 (2)	157 (4)
Symmetry code: (i) $[-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

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: 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/S1600536810006902/bt5200sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810006902/bt5200Isup2.hkl

checkCIF report

Related literature top

Pyrrolo[2,1-c][1,4]benzodiazepines are potent antibiotics produced by Streptomyces species; see: Cargill et al. (1974). For the design of DNA inter-strand cross-linkingand conjugate agents to enhance the sequence selectivity and selectivity for tumor cells, see: Gregson et al. (2004). Top of scheme cropped - please replace

Experimental top

2-Hydroxy-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-dione (2 g, 8.62 mmol), phenacyl bromide (1.7 g, 8.62 mmol), potassium carbonate (2.4 g, 17.24 mmol) and a catalytic quantity of tetra-n-butylammonium bromide was stirred under mild reflux in N,N-dimethylformamide (60 ml) for 48 h. The insoluble salts were filtered off and the solvent was removed under vacuum. The residue was separated by chromatography on silica gel with an n-hexane:ethyl acetate (3:7) solvent system. The compound was obtained as colorless crystals in 70% yield upon evaporation of the solvent.

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: 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 C₂₀H₁₈N₂O₄ at the 50% probability level; hydrogen atoms are drawn as arbitrary radius.

2-Hydroxy-10-phenacylpyrrolo[2,1-c][1,4]benzodiazepine-5,11-dione top

Crystal data top

C₂₀H₁₈N₂O₄	F(000) = 736
M_r = 350.36	D_x = 1.399 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 4805 reflections
a = 8.8337 (2) Å	θ = 3.0–29.4°
b = 9.9476 (2) Å	µ = 0.10 mm⁻¹
c = 18.9295 (4) Å	T = 293 K
V = 1663.41 (6) Å³	Block, colorless
Z = 4	0.3 × 0.3 × 0.3 mm

Data collection top

Bruker APEXII diffractometer	1967 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.030
Graphite monochromator	θ_max = 27.5°, θ_min = 2.2°
ϕ and ω scans	h = −11→11
12798 measured reflections	k = −12→12
2189 independent reflections	l = −24→24

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.118	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	w = 1/[σ²(F_o²) + (0.0831P)²] where P = (F_o² + 2F_c²)/3
2189 reflections	(Δ/σ)_max < 0.001
239 parameters	Δρ_max = 0.31 e Å⁻³
1 restraint	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₂₀H₁₈N₂O₄	V = 1663.41 (6) Å³
M_r = 350.36	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 8.8337 (2) Å	µ = 0.10 mm⁻¹
b = 9.9476 (2) Å	T = 293 K
c = 18.9295 (4) Å	0.3 × 0.3 × 0.3 mm

Data collection top

Bruker APEXII diffractometer	1967 reflections with I > 2σ(I)
12798 measured reflections	R_int = 0.030
2189 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	1 restraint
wR(F²) = 0.118	H atoms treated by a mixture of independent and constrained refinement
S = 1.15	Δρ_max = 0.31 e Å⁻³
2189 reflections	Δρ_min = −0.21 e Å⁻³
239 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	U_iso*/U_eq
O1	−0.0779 (2)	0.39357 (16)	0.24376 (9)	0.0502 (4)
O2	0.47486 (17)	0.28910 (19)	0.16152 (10)	0.0518 (4)
O3	0.1749 (3)	0.72478 (18)	0.14616 (10)	0.0573 (5)
H3	0.126 (4)	0.779 (3)	0.1712 (18)	0.096 (14)*
O4	0.4142 (2)	0.07005 (18)	0.02926 (9)	0.0558 (5)
N1	0.2550 (2)	0.18311 (17)	0.13852 (9)	0.0343 (4)
N2	0.1470 (2)	0.44132 (16)	0.19462 (9)	0.0352 (4)
C1	0.1014 (2)	0.18283 (19)	0.11457 (11)	0.0329 (4)
C2	0.0577 (3)	0.0859 (3)	0.06534 (14)	0.0500 (6)
H2	0.1291	0.0261	0.0476	0.060*
C3	−0.0909 (3)	0.0780 (3)	0.04276 (15)	0.0566 (7)
H3A	−0.1185	0.0117	0.0106	0.068*
C4	−0.1975 (3)	0.1657 (3)	0.06668 (14)	0.0520 (6)
H4	−0.2963	0.1613	0.0498	0.062*
C5	−0.1575 (3)	0.2611 (2)	0.11618 (13)	0.0412 (5)
H5	−0.2305	0.3202	0.1332	0.049*
C6	−0.0085 (2)	0.27020 (19)	0.14120 (10)	0.0325 (4)
C7	0.0178 (2)	0.37199 (19)	0.19761 (11)	0.0338 (4)
C8	0.1753 (3)	0.5578 (2)	0.23967 (11)	0.0407 (5)
H8A	0.2312	0.5325	0.2817	0.049*
H8B	0.0812	0.6006	0.2536	0.049*
C9	0.2686 (3)	0.6495 (2)	0.19265 (12)	0.0433 (5)
H9	0.3342	0.7085	0.2206	0.052*
C10	0.3610 (3)	0.5518 (2)	0.14819 (13)	0.0450 (6)
H10A	0.4529	0.5260	0.1727	0.054*
H10B	0.3880	0.5920	0.1032	0.054*
C11	0.2580 (2)	0.42975 (19)	0.13715 (11)	0.0332 (4)
H11	0.2078	0.4344	0.0911	0.040*
C12	0.3410 (2)	0.2959 (2)	0.14577 (11)	0.0342 (4)
C13	0.3331 (3)	0.0550 (2)	0.14878 (11)	0.0372 (4)
H13A	0.2586	−0.0142	0.1585	0.045*
H13B	0.3987	0.0621	0.1897	0.045*
C14	0.4276 (2)	0.0125 (2)	0.08502 (11)	0.0350 (4)
C15	0.5352 (2)	−0.10218 (19)	0.09258 (10)	0.0328 (4)
C16	0.5804 (3)	−0.1537 (2)	0.15741 (12)	0.0389 (5)
H16	0.5395	−0.1194	0.1989	0.047*
C17	0.6868 (3)	−0.2567 (3)	0.16037 (15)	0.0503 (6)
H17	0.7175	−0.2902	0.2039	0.060*
C18	0.7472 (3)	−0.3094 (3)	0.09913 (16)	0.0546 (6)
H18	0.8188	−0.3778	0.1014	0.065*
C19	0.7009 (3)	−0.2605 (2)	0.03459 (15)	0.0500 (6)
H19	0.7405	−0.2967	−0.0068	0.060*
C20	0.5961 (2)	−0.1579 (2)	0.03106 (12)	0.0406 (5)
H20	0.5656	−0.1255	−0.0128	0.049*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0493 (9)	0.0446 (8)	0.0566 (9)	−0.0037 (8)	0.0283 (8)	−0.0046 (8)
O2	0.0303 (7)	0.0521 (10)	0.0730 (11)	0.0000 (8)	−0.0009 (8)	−0.0129 (9)
O3	0.0768 (13)	0.0405 (9)	0.0548 (11)	0.0056 (10)	0.0169 (10)	0.0012 (8)
O4	0.0678 (12)	0.0546 (10)	0.0450 (9)	0.0199 (10)	0.0092 (9)	0.0123 (8)
N1	0.0318 (8)	0.0296 (8)	0.0415 (9)	0.0026 (7)	0.0014 (7)	−0.0074 (7)
N2	0.0379 (9)	0.0292 (8)	0.0385 (8)	−0.0043 (7)	0.0131 (8)	−0.0076 (7)
C1	0.0327 (9)	0.0300 (9)	0.0360 (9)	−0.0053 (8)	0.0024 (8)	−0.0021 (8)
C2	0.0461 (12)	0.0484 (13)	0.0555 (14)	−0.0071 (11)	0.0008 (11)	−0.0178 (11)
C3	0.0553 (14)	0.0611 (15)	0.0535 (14)	−0.0201 (14)	−0.0088 (12)	−0.0107 (12)
C4	0.0378 (11)	0.0618 (15)	0.0563 (14)	−0.0151 (12)	−0.0092 (11)	0.0121 (12)
C5	0.0318 (10)	0.0429 (11)	0.0490 (12)	−0.0046 (9)	0.0025 (10)	0.0128 (10)
C6	0.0321 (9)	0.0295 (8)	0.0360 (9)	−0.0046 (8)	0.0062 (8)	0.0051 (8)
C7	0.0352 (9)	0.0281 (9)	0.0381 (9)	0.0006 (9)	0.0097 (9)	0.0017 (7)
C8	0.0507 (12)	0.0329 (9)	0.0386 (10)	−0.0039 (10)	0.0101 (10)	−0.0110 (8)
C9	0.0497 (12)	0.0326 (10)	0.0474 (11)	−0.0085 (10)	0.0093 (11)	−0.0134 (9)
C10	0.0436 (12)	0.0360 (10)	0.0553 (13)	−0.0132 (10)	0.0165 (11)	−0.0136 (9)
C11	0.0335 (9)	0.0300 (9)	0.0362 (9)	−0.0055 (8)	0.0091 (9)	−0.0063 (8)
C12	0.0301 (9)	0.0355 (10)	0.0369 (10)	−0.0017 (9)	0.0060 (8)	−0.0093 (8)
C13	0.0402 (10)	0.0307 (9)	0.0408 (10)	0.0028 (9)	0.0047 (10)	−0.0018 (8)
C14	0.0365 (10)	0.0295 (9)	0.0390 (10)	−0.0022 (9)	0.0040 (9)	−0.0017 (8)
C15	0.0315 (9)	0.0270 (8)	0.0398 (10)	−0.0044 (8)	0.0028 (8)	−0.0048 (7)
C16	0.0387 (10)	0.0365 (10)	0.0415 (10)	−0.0023 (9)	0.0015 (9)	−0.0023 (8)
C17	0.0469 (13)	0.0456 (12)	0.0586 (14)	0.0048 (12)	−0.0040 (12)	0.0076 (11)
C18	0.0435 (12)	0.0422 (12)	0.0781 (18)	0.0112 (11)	0.0071 (13)	−0.0013 (12)
C19	0.0460 (13)	0.0426 (12)	0.0615 (14)	0.0023 (11)	0.0118 (11)	−0.0147 (11)
C20	0.0419 (11)	0.0400 (11)	0.0401 (10)	−0.0025 (10)	0.0065 (9)	−0.0082 (9)

Geometric parameters (Å, º) top

O1—C7	1.235 (2)	C8—H8B	0.9700
O2—C12	1.221 (3)	C9—C10	1.523 (3)
O3—C9	1.421 (3)	C9—H9	0.9800
O3—H3	0.841 (10)	C10—C11	1.531 (3)
O4—C14	1.207 (3)	C10—H10A	0.9700
N1—C12	1.362 (3)	C10—H10B	0.9700
N1—C1	1.430 (3)	C11—C12	1.529 (3)
N1—C13	1.462 (3)	C11—H11	0.9800
N2—C7	1.334 (3)	C13—C14	1.528 (3)
N2—C8	1.460 (2)	C13—H13A	0.9700
N2—C11	1.469 (2)	C13—H13B	0.9700
C1—C2	1.396 (3)	C14—C15	1.492 (3)
C1—C6	1.397 (3)	C15—C16	1.389 (3)
C2—C3	1.383 (4)	C15—C20	1.397 (3)
C2—H2	0.9300	C16—C17	1.391 (3)
C3—C4	1.361 (4)	C16—H16	0.9300
C3—H3A	0.9300	C17—C18	1.379 (4)
C4—C5	1.380 (4)	C17—H17	0.9300
C4—H4	0.9300	C18—C19	1.377 (4)
C5—C6	1.402 (3)	C18—H18	0.9300
C5—H5	0.9300	C19—C20	1.379 (3)
C6—C7	1.490 (3)	C19—H19	0.9300
C8—C9	1.518 (3)	C20—H20	0.9300
C8—H8A	0.9700

C9—O3—H3	107 (3)	C9—C10—H10A	110.7
C12—N1—C1	124.24 (17)	C11—C10—H10A	110.7
C12—N1—C13	116.19 (16)	C9—C10—H10B	110.7
C1—N1—C13	119.21 (17)	C11—C10—H10B	110.7
C7—N2—C8	122.12 (17)	H10A—C10—H10B	108.8
C7—N2—C11	124.18 (16)	N2—C11—C12	108.02 (17)
C8—N2—C11	112.35 (16)	N2—C11—C10	103.50 (16)
C2—C1—C6	118.6 (2)	C12—C11—C10	113.01 (18)
C2—C1—N1	118.36 (19)	N2—C11—H11	110.7
C6—C1—N1	122.92 (17)	C12—C11—H11	110.7
C3—C2—C1	120.5 (2)	C10—C11—H11	110.7
C3—C2—H2	119.7	O2—C12—N1	121.3 (2)
C1—C2—H2	119.7	O2—C12—C11	122.6 (2)
C4—C3—C2	121.2 (2)	N1—C12—C11	116.05 (16)
C4—C3—H3A	119.4	N1—C13—C14	113.23 (17)
C2—C3—H3A	119.4	N1—C13—H13A	108.9
C3—C4—C5	119.3 (2)	C14—C13—H13A	108.9
C3—C4—H4	120.4	N1—C13—H13B	108.9
C5—C4—H4	120.4	C14—C13—H13B	108.9
C4—C5—C6	121.0 (2)	H13A—C13—H13B	107.7
C4—C5—H5	119.5	O4—C14—C15	120.62 (19)
C6—C5—H5	119.5	O4—C14—C13	120.4 (2)
C1—C6—C5	119.35 (19)	C15—C14—C13	118.97 (17)
C1—C6—C7	124.96 (18)	C16—C15—C20	118.63 (19)
C5—C6—C7	115.64 (19)	C16—C15—C14	123.39 (18)
O1—C7—N2	121.73 (19)	C20—C15—C14	117.96 (18)
O1—C7—C6	121.22 (19)	C15—C16—C17	120.1 (2)
N2—C7—C6	117.01 (17)	C15—C16—H16	119.9
N2—C8—C9	103.16 (16)	C17—C16—H16	119.9
N2—C8—H8A	111.1	C18—C17—C16	120.5 (2)
C9—C8—H8A	111.1	C18—C17—H17	119.8
N2—C8—H8B	111.1	C16—C17—H17	119.8
C9—C8—H8B	111.1	C19—C18—C17	119.8 (2)
H8A—C8—H8B	109.1	C19—C18—H18	120.1
O3—C9—C8	111.3 (2)	C17—C18—H18	120.1
O3—C9—C10	107.82 (19)	C18—C19—C20	120.2 (2)
C8—C9—C10	103.35 (17)	C18—C19—H19	119.9
O3—C9—H9	111.3	C20—C19—H19	119.9
C8—C9—H9	111.3	C19—C20—C15	120.8 (2)
C10—C9—H9	111.3	C19—C20—H20	119.6
C9—C10—C11	105.27 (17)	C15—C20—H20	119.6

C12—N1—C1—C2	136.0 (2)	C8—N2—C11—C12	119.19 (19)
C13—N1—C1—C2	−36.8 (3)	C7—N2—C11—C10	166.1 (2)
C12—N1—C1—C6	−47.7 (3)	C8—N2—C11—C10	−0.9 (2)
C13—N1—C1—C6	139.5 (2)	C9—C10—C11—N2	−20.6 (2)
C6—C1—C2—C3	0.9 (4)	C9—C10—C11—C12	−137.16 (19)
N1—C1—C2—C3	177.4 (3)	C1—N1—C12—O2	−174.6 (2)
C1—C2—C3—C4	1.3 (5)	C13—N1—C12—O2	−1.6 (3)
C2—C3—C4—C5	−2.2 (4)	C1—N1—C12—C11	8.7 (3)
C3—C4—C5—C6	1.0 (4)	C13—N1—C12—C11	−178.27 (17)
C2—C1—C6—C5	−2.1 (3)	N2—C11—C12—O2	−112.3 (2)
N1—C1—C6—C5	−178.35 (18)	C10—C11—C12—O2	1.6 (3)
C2—C1—C6—C7	175.3 (2)	N2—C11—C12—N1	64.4 (2)
N1—C1—C6—C7	−0.9 (3)	C10—C11—C12—N1	178.29 (18)
C4—C5—C6—C1	1.1 (3)	C12—N1—C13—C14	−78.0 (2)
C4—C5—C6—C7	−176.5 (2)	C1—N1—C13—C14	95.4 (2)
C8—N2—C7—O1	−7.9 (3)	N1—C13—C14—O4	−11.8 (3)
C11—N2—C7—O1	−173.6 (2)	N1—C13—C14—C15	168.91 (16)
C8—N2—C7—C6	170.02 (18)	O4—C14—C15—C16	165.7 (2)
C11—N2—C7—C6	4.3 (3)	C13—C14—C15—C16	−15.1 (3)
C1—C6—C7—O1	−140.7 (2)	O4—C14—C15—C20	−12.7 (3)
C5—C6—C7—O1	36.8 (3)	C13—C14—C15—C20	166.57 (19)
C1—C6—C7—N2	41.3 (3)	C20—C15—C16—C17	1.4 (3)
C5—C6—C7—N2	−141.1 (2)	C14—C15—C16—C17	−176.9 (2)
C7—N2—C8—C9	−145.4 (2)	C15—C16—C17—C18	−0.7 (4)
C11—N2—C8—C9	21.8 (2)	C16—C17—C18—C19	−0.5 (4)
N2—C8—C9—O3	82.0 (2)	C17—C18—C19—C20	0.8 (4)
N2—C8—C9—C10	−33.5 (2)	C18—C19—C20—C15	0.0 (4)
O3—C9—C10—C11	−84.2 (2)	C16—C15—C20—C19	−1.1 (3)
C8—C9—C10—C11	33.8 (2)	C14—C15—C20—C19	177.3 (2)
C7—N2—C11—C12	−73.9 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1ⁱ	0.84 (1)	2.02 (2)	2.810 (2)	157 (4)

Symmetry code: (i) −x, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₂₀H₁₈N₂O₄
M_r	350.36
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	8.8337 (2), 9.9476 (2), 18.9295 (4)
V (Å³)	1663.41 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.3 × 0.3 × 0.3

Data collection
Diffractometer	Bruker APEXII diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	12798, 2189, 1967
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.118, 1.15
No. of reflections	2189
No. of parameters	239
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.31, −0.21

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1ⁱ	0.84 (1)	2.02 (2)	2.810 (2)	157 (4)

Symmetry code: (i) −x, y+1/2, −z+1/2.

Acknowledgements

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

References

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