4-(4-Methoxy­phen­yl)-3-methyl-1,6-di­oxa-2,8-diaza-s-indacen-5(7H)-one

Zhang, L.-X.; Zhang, X.-H.; Yan, S.

doi:10.1107/S1600536809013373

organic compounds

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ISSN: 2056-9890

Volume 65| Part 5| May 2009| Page o1054

doi:10.1107/S1600536809013373

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4-(4-Methoxyphenyl)-3-methyl-1,6-dioxa-2,8-diaza-s-indacen-5(7H)-one

Li-Xin Zhang,^a ^* Xiao-Hong Zhang ^a and Shu Yan ^a

^aCollege of Chemistry and Chemical Engineering, Xuzhou Normal University, Xuzhou 221116, People's Republic of China
^*Correspondence e-mail: xhzhang1119@sohu.com

(Received 7 April 2009; accepted 8 April 2009; online 18 April 2009)

In the molecule of the title compound, C₁₆H₁₂N₂O₄, the pyridine ring is oriented at the same dihedral angle of 2.92 (3)° with respect to the furan and isoxazole rings, while the dihedral angle between furan and isoxazole rings is 1.34 (3)°. The dihedral angle between the benzene and pyridine rings is 53.23 (3)°. In the crystal structure, intermolecular C—H⋯O interactions link the molecules into chains. Weak π–π contacts between isoxazole and benzene rings [centroid–centroid distance = 3.969 (3) Å] may further stabilize the structure.

Related literature

For general background to isoxazoles, see: Pinho & Teresa (2005 ); Shin et al. (2005 ); Tatee et al. (1987 ). For a related structure, see: Chande et al. (2005 ). For bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₁₆H₁₂N₂O₄
M_r = 296.28
Monoclinic, P 2₁ /c
a = 13.8513 (16) Å
b = 7.6116 (11) Å
c = 12.6732 (15) Å
β = 95.592 (1)°
V = 1329.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 298 K
0.14 × 0.11 × 0.05 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.985, T_max = 0.995
6625 measured reflections
2333 independent reflections
1267 reflections with I > 2σ(I)
R_int = 0.085

Refinement

R[F² > 2σ(F²)] = 0.058
wR(F²) = 0.093
S = 1.03
2333 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.14 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
C2—H2B⋯O2ⁱ	0.97	2.39	3.215 (3)	143
Symmetry code: (i) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 1998 ); cell refinement: SAINT (Bruker, 1998); 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, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809013373/hk2664sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809013373/hk2664Isup2.hkl

checkCIF report

Comment top

Isoxazole is one of the important heterocyclic units, which has been widely used as a key building block for pharmaceutical agents. Its derivatives are endowed with many pharmacological properties, such as hypoglycemic, analgesic, anti-inflammatory, anti-bacterial, anti-cancer and anti-HIV activities (Shin et al., 2005). Besides, they also have agrochemical properties including herbicidal and soil fungicidal activities, thus they have been used as pesticides and insecticides (Pinho & Teresa, 2005). Among the derivatives of isoxazole, isoxazolopyridine has evoked people's interest and concern, since it showed muscle relaxant, anticonvulsant and CNS depressant activities (Tatee et al., 1987). To the best of our knowledge, modification and synthesis of polycyclic-fused isoxazolopyridine have never been reported. Thus, synthesis of structurally diverse isoxazole-based (Chande et al., 2005) small molecules is of great significance. We report herein the crystal structure of the title compound.

In the molecule of the title compound (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges. Rings A (O1/C1-C4), B (O3/N2/C6-C8), C (N1/C1/C4-C7) and D (C10-C15) are, of course, planar, and they are oriented at dihedral angles of A/B = 1.34 (3), A/C = 2.92 (3), A/D = 56.13 (4), B/C = 2.92 (3), B/D = 55.97 (4) and C/D = 53.23 (3) °.

In the crystal structure, intermolecular C-H···O interactions (Table 1) link the molecules into chains (Fig. 2), in which they may be effective in the stabilization of the structure. The π–π contact between the isoxazole and phenyl rings, Cg2—Cg4ⁱ [symmetry code: (i) x, 3/2 - y, z + 1/2, where Cg2 and Cg4 are centroids of the rings B (O3/N2/C6-C8) and D (C10-C15), respectively] may further stabilize the structure, with centroid-centroid distance of 3.969 (3) Å.

Related literature top

For general background to isoxazoles, see: Pinho & Teresa (2005); Shin et al. (2005); Tatee et al. (1987). For a related structure, see: Chande et al. (2005). For bond-length data, see: Allen et al. (1987).

Experimental top

The title compound was prepared by the reaction of 4-methoxybenzaldehyde (1 mmol), tetronic acid (1 mmol) and 3-methylisoxazol-5-amine (1 mmol) in water (2 ml). Crystals suitable for X-ray analysis were obtained by slow evaporation of an aqueous ethanol solution (95%) (yield; 91%, m.p. 504-506 K). IR (cm^-1): 1759; ¹H NMR (DMSO-d₆): 7.56 (d, 2H, J = 8.8 Hz, ArH), 7.12 (d, 2H, J = 8.8 Hz, ArH), 5.49 (s, 2H, CH2), 3.87 (s, 3H, OCH3), 2.16 (s, 3H, CH3); ¹³C NMR (DMSO-d₆): 171.84, 170.16, 167.00, 160.71, 157.07, 149.38, 131.54, 121.73, 113.40, 113.30, 112.89, 68.72, 55.30, 12.86.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); 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, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A partial packing diagram of the title compound. Hydrogen bonds are shown as dashed lines.

4-(4-Methoxyphenyl)-3-methyl-1,6-dioxa-2,8-diaza-s- indacen-5(7H)-one top

Crystal data top

C₁₆H₁₂N₂O₄	F(000) = 616
M_r = 296.28	D_x = 1.480 Mg m⁻³
Monoclinic, P2₁/c	Melting point = 504–506 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 13.8513 (16) Å	Cell parameters from 1263 reflections
b = 7.6116 (11) Å	θ = 3.0–27.5°
c = 12.6732 (15) Å	µ = 0.11 mm⁻¹
β = 95.592 (1)°	T = 298 K
V = 1329.8 (3) Å³	Block, colorless
Z = 4	0.14 × 0.11 × 0.05 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	2333 independent reflections
Radiation source: fine-focus sealed tube	1267 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.085
ϕ and ω scans	θ_max = 25.0°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −16→16
T_min = 0.985, T_max = 0.995	k = −5→9
6625 measured reflections	l = −15→15

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)] = 0.058	H-atom parameters constrained
wR(F²) = 0.093	w = 1/[σ²(F_o²) + (0.0242P)²] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
2333 reflections	Δρ_max = 0.14 e Å⁻³
201 parameters	Δρ_min = −0.19 e Å⁻³
Primary atom site location: structure-invariant direct methods

Crystal data top

C₁₆H₁₂N₂O₄	V = 1329.8 (3) Å³
M_r = 296.28	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 13.8513 (16) Å	µ = 0.11 mm⁻¹
b = 7.6116 (11) Å	T = 298 K
c = 12.6732 (15) Å	0.14 × 0.11 × 0.05 mm
β = 95.592 (1)°

Data collection top

Bruker SMART CCD area-detector diffractometer	2333 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1267 reflections with I > 2σ(I)
T_min = 0.985, T_max = 0.995	R_int = 0.085
6625 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.058	201 parameters
wR(F²) = 0.093	H-atom parameters constrained
S = 1.03	Δρ_max = 0.14 e Å⁻³
2333 reflections	Δρ_min = −0.19 e Å⁻³

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
N1	0.19564 (17)	−0.0001 (3)	0.93775 (17)	0.0496 (6)
N2	0.42384 (17)	−0.1679 (3)	0.8929 (2)	0.0646 (7)
O1	−0.00728 (12)	0.1886 (3)	0.77882 (13)	0.0530 (5)
O2	0.03096 (12)	0.1945 (3)	0.61265 (14)	0.0561 (5)
O3	0.35098 (14)	−0.1183 (3)	0.95948 (14)	0.0625 (6)
O4	0.30666 (13)	0.0742 (2)	0.28784 (14)	0.0553 (6)
C1	0.1314 (2)	0.0595 (3)	0.8621 (2)	0.0413 (7)
C2	0.03488 (19)	0.1313 (4)	0.8820 (2)	0.0545 (8)
H2A	−0.0049	0.0415	0.9106	0.065*
H2B	0.0418	0.2291	0.9312	0.065*
C3	0.05378 (18)	0.1546 (4)	0.7033 (2)	0.0431 (7)
C4	0.14180 (18)	0.0708 (3)	0.75423 (18)	0.0371 (6)
C5	0.22780 (17)	0.0190 (3)	0.71290 (19)	0.0364 (6)
C6	0.29723 (19)	−0.0463 (3)	0.7918 (2)	0.0411 (7)
C7	0.2760 (2)	−0.0493 (4)	0.8971 (2)	0.0461 (7)
C8	0.3921 (2)	−0.1270 (4)	0.7960 (2)	0.0496 (7)
C9	0.45235 (19)	−0.1739 (4)	0.7089 (2)	0.0653 (9)
H9A	0.4837	−0.0703	0.6857	0.098*
H9B	0.4117	−0.2232	0.6507	0.098*
H9C	0.5006	−0.2584	0.7344	0.098*
C10	0.24536 (17)	0.0332 (3)	0.60100 (18)	0.0366 (6)
C11	0.18199 (17)	−0.0388 (3)	0.52099 (19)	0.0410 (7)
H11	0.1263	−0.0955	0.5385	0.049*
C12	0.19987 (17)	−0.0281 (3)	0.41641 (19)	0.0424 (7)
H12	0.1567	−0.0784	0.3642	0.051*
C13	0.28166 (18)	0.0570 (4)	0.3886 (2)	0.0411 (7)
C14	0.34544 (18)	0.1327 (3)	0.4676 (2)	0.0438 (7)
H14	0.4002	0.1921	0.4498	0.053*
C15	0.32724 (17)	0.1194 (3)	0.5715 (2)	0.0420 (7)
H15	0.3706	0.1691	0.6237	0.050*
C16	0.2431 (2)	0.0018 (4)	0.2031 (2)	0.0576 (8)
H16A	0.2355	−0.1219	0.2145	0.086*
H16B	0.2703	0.0203	0.1371	0.086*
H16C	0.1810	0.0584	0.2008	0.086*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0622 (16)	0.0493 (17)	0.0355 (14)	−0.0014 (14)	−0.0045 (12)	0.0028 (12)
N2	0.0610 (16)	0.0695 (19)	0.0598 (18)	0.0076 (15)	−0.0117 (14)	0.0066 (14)
O1	0.0524 (11)	0.0708 (14)	0.0364 (12)	0.0069 (11)	0.0064 (9)	0.0018 (10)
O2	0.0512 (11)	0.0798 (15)	0.0365 (12)	0.0089 (11)	0.0012 (9)	0.0128 (11)
O3	0.0690 (13)	0.0704 (16)	0.0447 (13)	0.0046 (12)	−0.0123 (11)	0.0081 (11)
O4	0.0597 (12)	0.0746 (15)	0.0319 (12)	−0.0042 (11)	0.0065 (10)	−0.0003 (10)
C1	0.0515 (16)	0.0396 (18)	0.0320 (16)	−0.0066 (14)	−0.0008 (13)	−0.0008 (13)
C2	0.0623 (19)	0.067 (2)	0.0340 (17)	−0.0022 (17)	0.0060 (14)	−0.0004 (15)
C3	0.0476 (17)	0.048 (2)	0.0345 (17)	−0.0057 (15)	0.0068 (14)	−0.0007 (14)
C4	0.0417 (15)	0.0376 (17)	0.0311 (16)	−0.0049 (13)	−0.0001 (12)	0.0018 (12)
C5	0.0430 (15)	0.0349 (17)	0.0294 (15)	−0.0061 (13)	−0.0056 (12)	−0.0006 (12)
C6	0.0458 (16)	0.0413 (18)	0.0351 (17)	−0.0052 (14)	−0.0020 (13)	−0.0021 (13)
C7	0.0537 (18)	0.0376 (19)	0.0431 (19)	−0.0019 (15)	−0.0154 (15)	0.0031 (14)
C8	0.0483 (17)	0.049 (2)	0.0489 (19)	−0.0036 (16)	−0.0102 (14)	−0.0005 (15)
C9	0.0561 (18)	0.069 (2)	0.069 (2)	0.0130 (18)	−0.0001 (16)	0.0028 (17)
C10	0.0384 (15)	0.0395 (18)	0.0310 (16)	0.0010 (13)	−0.0012 (12)	0.0006 (12)
C11	0.0371 (15)	0.0471 (19)	0.0385 (18)	−0.0041 (13)	0.0015 (12)	0.0026 (13)
C12	0.0411 (16)	0.050 (2)	0.0339 (17)	−0.0022 (15)	−0.0058 (13)	−0.0066 (13)
C13	0.0441 (16)	0.0436 (19)	0.0355 (17)	0.0061 (14)	0.0030 (13)	−0.0004 (13)
C14	0.0389 (15)	0.051 (2)	0.0418 (18)	−0.0034 (14)	0.0049 (13)	0.0020 (14)
C15	0.0380 (15)	0.0470 (19)	0.0393 (17)	−0.0039 (14)	−0.0052 (12)	−0.0028 (14)
C16	0.080 (2)	0.057 (2)	0.0342 (17)	0.0050 (18)	−0.0010 (15)	−0.0030 (15)

Geometric parameters (Å, º) top

N1—C1	1.324 (3)	C6—C8	1.446 (3)
N1—C7	1.325 (3)	C8—C9	1.490 (4)
N2—C8	1.302 (3)	C9—H9A	0.9600
N2—O3	1.428 (3)	C9—H9B	0.9600
O1—C3	1.363 (3)	C9—H9C	0.9600
O1—C2	1.446 (3)	C10—C11	1.388 (3)
O2—C3	1.200 (3)	C10—C15	1.393 (3)
O3—C7	1.349 (3)	C11—C12	1.374 (3)
O4—C13	1.361 (3)	C11—H11	0.9300
O4—C16	1.431 (3)	C12—C13	1.380 (3)
C1—C4	1.391 (3)	C12—H12	0.9300
C1—C2	1.488 (3)	C13—C14	1.394 (3)
C2—H2A	0.9700	C14—C15	1.368 (3)
C2—H2B	0.9700	C14—H14	0.9300
C3—C4	1.469 (3)	C15—H15	0.9300
C4—C5	1.404 (3)	C16—H16A	0.9600
C5—C6	1.409 (3)	C16—H16B	0.9600
C5—C10	1.466 (3)	C16—H16C	0.9600
C6—C7	1.395 (3)

C1—N1—C7	110.3 (2)	C6—C8—C9	130.3 (3)
C8—N2—O3	107.5 (2)	C8—C9—H9A	109.5
C3—O1—C2	110.7 (2)	C8—C9—H9B	109.5
C7—O3—N2	107.8 (2)	H9A—C9—H9B	109.5
C13—O4—C16	118.2 (2)	C8—C9—H9C	109.5
N1—C1—C4	127.3 (3)	H9A—C9—H9C	109.5
N1—C1—C2	123.7 (2)	H9B—C9—H9C	109.5
C4—C1—C2	109.0 (2)	C11—C10—C15	117.6 (2)
O1—C2—C1	104.4 (2)	C11—C10—C5	121.7 (2)
O1—C2—H2A	110.9	C15—C10—C5	120.7 (2)
C1—C2—H2A	110.9	C12—C11—C10	121.4 (2)
O1—C2—H2B	110.9	C12—C11—H11	119.3
C1—C2—H2B	110.9	C10—C11—H11	119.3
H2A—C2—H2B	108.9	C11—C12—C13	120.2 (2)
O2—C3—O1	120.0 (2)	C11—C12—H12	119.9
O2—C3—C4	131.4 (2)	C13—C12—H12	119.9
O1—C3—C4	108.6 (2)	O4—C13—C12	125.1 (2)
C1—C4—C5	121.5 (2)	O4—C13—C14	115.6 (2)
C1—C4—C3	107.3 (2)	C12—C13—C14	119.3 (2)
C5—C4—C3	131.0 (2)	C15—C14—C13	119.8 (2)
C4—C5—C6	112.3 (2)	C15—C14—H14	120.1
C4—C5—C10	124.6 (2)	C13—C14—H14	120.1
C6—C5—C10	123.1 (2)	C14—C15—C10	121.7 (2)
C7—C6—C5	119.5 (3)	C14—C15—H15	119.2
C7—C6—C8	103.5 (2)	C10—C15—H15	119.2
C5—C6—C8	136.9 (3)	O4—C16—H16A	109.5
N1—C7—O3	120.7 (3)	O4—C16—H16B	109.5
N1—C7—C6	129.1 (3)	H16A—C16—H16B	109.5
O3—C7—C6	110.2 (3)	O4—C16—H16C	109.5
N2—C8—C6	111.0 (2)	H16A—C16—H16C	109.5
N2—C8—C9	118.6 (3)	H16B—C16—H16C	109.5

C8—N2—O3—C7	0.6 (3)	N2—O3—C7—C6	−1.7 (3)
C7—N1—C1—C4	0.6 (4)	C5—C6—C7—N1	1.1 (4)
C7—N1—C1—C2	−177.6 (2)	C8—C6—C7—N1	−176.1 (3)
C3—O1—C2—C1	1.0 (3)	C5—C6—C7—O3	179.2 (2)
N1—C1—C2—O1	176.8 (2)	C8—C6—C7—O3	2.0 (3)
C4—C1—C2—O1	−1.6 (3)	O3—N2—C8—C6	0.7 (3)
C2—O1—C3—O2	−179.5 (2)	O3—N2—C8—C9	−176.8 (2)
C2—O1—C3—C4	0.0 (3)	C7—C6—C8—N2	−1.7 (3)
N1—C1—C4—C5	−1.1 (4)	C5—C6—C8—N2	−178.1 (3)
C2—C1—C4—C5	177.3 (2)	C7—C6—C8—C9	175.4 (3)
N1—C1—C4—C3	−176.8 (3)	C5—C6—C8—C9	−1.0 (5)
C2—C1—C4—C3	1.7 (3)	C4—C5—C10—C11	−53.8 (4)
O2—C3—C4—C1	178.3 (3)	C6—C5—C10—C11	127.3 (3)
O1—C3—C4—C1	−1.1 (3)	C4—C5—C10—C15	126.5 (3)
O2—C3—C4—C5	3.2 (5)	C6—C5—C10—C15	−52.4 (4)
O1—C3—C4—C5	−176.1 (2)	C15—C10—C11—C12	1.0 (4)
C1—C4—C5—C6	1.4 (3)	C5—C10—C11—C12	−178.7 (2)
C3—C4—C5—C6	175.9 (3)	C10—C11—C12—C13	−0.7 (4)
C1—C4—C5—C10	−177.6 (2)	C16—O4—C13—C12	1.1 (4)
C3—C4—C5—C10	−3.1 (4)	C16—O4—C13—C14	−179.0 (2)
C4—C5—C6—C7	−1.4 (3)	C11—C12—C13—O4	179.5 (2)
C10—C5—C6—C7	177.7 (2)	C11—C12—C13—C14	−0.4 (4)
C4—C5—C6—C8	174.6 (3)	O4—C13—C14—C15	−178.8 (2)
C10—C5—C6—C8	−6.4 (5)	C12—C13—C14—C15	1.1 (4)
C1—N1—C7—O3	−178.5 (2)	C13—C14—C15—C10	−0.8 (4)
C1—N1—C7—C6	−0.6 (4)	C11—C10—C15—C14	−0.3 (4)
N2—O3—C7—N1	176.5 (2)	C5—C10—C15—C14	179.4 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2B···O2ⁱ	0.97	2.39	3.215 (3)	143

Symmetry code: (i) x, −y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₆H₁₂N₂O₄
M_r	296.28
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	13.8513 (16), 7.6116 (11), 12.6732 (15)
β (°)	95.592 (1)
V (Å³)	1329.8 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.14 × 0.11 × 0.05

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.985, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	6625, 2333, 1267
R_int	0.085
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.058, 0.093, 1.03
No. of reflections	2333
No. of parameters	201
No. of restraints	?
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.14, −0.19

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2B···O2ⁱ	0.97	2.39	3.215 (3)	143

Symmetry code: (i) x, −y+1/2, z+1/2.

Acknowledgements

The authors thank the National Natural Science Foundation of China (grant No. 20672090) and the Natural Science Foundation of Jiangsu Province (grant No. BK2006033) for financial support.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chande, M. S., Verma, R. S., Barve, P. A., Khanwelkar, R. R., Vaidya, R. B. & Ajaikumar, K. B. (2005). Eur. J. Med. Chem. 40, 1143–1148. Web of Science CrossRef PubMed CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Pinho, E. M. & Teresa, M. V. D. (2005). Curr. Org. Chem. 9, 925–958. Google Scholar
Sheldrick, G. M. (1996). 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
Shin, K. D., Lee, M. Y., Shin, D. S., Lee, S., Son, K. H., Koh, S., Paik, Y. K., Kwon, B. M. & Han, D. C. (2005). J. Biol. Chem. 280, 41439–41448. Web of Science CrossRef PubMed CAS Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tatee, T., Narita, K., Kurashige, S., Ito, S., Miyazaki, H., Yamanaka, H., Mizugaki, M., Sakamoto, T. & Fukuda, H. (1987). Chem. Pharm. Bull. 35, 3676–3690. CrossRef CAS PubMed Web of Science Google Scholar