2-(1-Ethyl-5-meth­oxy-1H-indol-3-yl)-N-isopropyl-2-oxoacetamide

Tang, X.-W.; Zhu, T.-L.; Chen, H.; Tian, D.-L.; Shi, S.-Y.

doi:10.1107/S1600536811012815

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 67| Part 5| May 2011| Page o1158

doi:10.1107/S1600536811012815

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2-(1-Ethyl-5-methoxy-1H-indol-3-yl)-N-isopropyl-2-oxoacetamide

Xiao-Wei Tang,^a Tie-Liang Zhu,^b Hong Chen,^b,^c ^* Dan-Li Tian ^a and Shao-Yu Shi ^a

^aSchool of Pharmacy, Tianjin Medical University, Tianjin 300070, People's Republic of China, ^bMedical College of Chinese People's Armed Police Forces, Tianjin 300162, People's Republic of China, and ^cTianjin Key Laboratory for Biomarkers of Occupational and Environmental Hazards, Tianjin 300162, People's Republic of China
^*Correspondence e-mail: tjch2010@yahoo.cn

(Received 29 March 2011; accepted 6 April 2011; online 16 April 2011)

In the title compound, C₁₆H₂₀N₂O₃, the crystal packing is stabilized by weak π–π stacking interactions [centroid–centroid distances = 3.577 (9) and 3.693 (9) Å] and intermolecular C—H⋯O and N—H⋯O hydrogen-bond interactions. The C atoms of the N-isopropyl group are disordered over two sets of sites with occupancies of 0.61(3) and 0.39(3).

Related literature

For the biological activity of the title compound and its derivatives, see: Souli et al. (2008 ); Chai et al. (2006 ); Radwan et al. (2007 ); Karthikeyan et al. (2009 ). For the preparation, see: Bacher et al. (2001 ). For bond lengths and angles in similar structures, see: Feng et al. (2008 ); Sonar et al. (2006 ).

Experimental

Crystal data

C₁₆H₂₀N₂O₃
M_r = 288.34
Orthorhombic, P b c a
a = 11.593 (3) Å
b = 9.182 (2) Å
c = 27.796 (6) Å
V = 2958.8 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 113 K
0.30 × 0.24 × 0.10 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ) T_min = 0.974, T_max = 0.991
25486 measured reflections
3527 independent reflections
3320 reflections with I > 2σ(I)
R_int = 0.053

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.133
S = 1.12
3527 reflections
204 parameters
39 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯O2ⁱ	0.95	2.54	3.4874 (17)	172
N2—H2B⋯O3ⁱⁱ	0.894 (19)	2.149 (19)	2.9933 (17)	157.2 (16)
Symmetry codes: (i) $[x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]$ ; (ii) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z]$ .

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811012815/hg5020sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811012815/hg5020Isup2.hkl

checkCIF report

Comment top

Indole and their derivatives are well known as substances with biologically activity such as anti-cancer (Souli et al., 2008), anti-virus (Chai et al., 2006), anti-tubercular (Karthikeyan et al., 2009), and anti-inflammatory (Radwan et al., 2007). In recent years, our recent study is paying attention to synthesize different kinds of indole derivatives with improved bioactivities. In this paper, we reported the crystal structure of the title compound.

In title compound, C₁₆H₂₀N₂O₃, bond lengths and angles are normal and in good agreement with those reported previously (Feng et al., 2008; Sonar, et al., 2006). π—π interactions are indicated by the short distance (Cg1···Cg2 distance of 3.693 (9) Å, Cg2···Cg2 distance of 3.577 (9)Å symmetry code: 1 - x,1 - y,-z) between the centroids of the pyrrole ring (N1/C1/C6—C8) (Cg1) and benzene ring C1—C6 (Cg2) (Table 1). There are weaker C—H···O and N—H···O intermolecular interactions, which stabilized the structure (Table 1).

Related literature top

For the biological activity of the title compound and its derivatives, see: Souli et al. (2008); Chai et al. (2006); Radwan et al. (2007); Karthikeyan et al. (2009). For the preparation, see: Bacher et al. (2001). For bond lengths and angles in similar structures, see: Feng et al. (2008); Sonar et al. (2006).

Experimental top

The target compound was synthesized by three steps. Under ice bath, DMF solution of 5-methoxy indole was added dropwise to DMF solution of NaH 0.5 h later, ethyl bromide was added. The reaction solvent add into ice water, and the compound is separated from the liquid after stirring. Oxalyl chloride was added dropwise to the 1-ethyl-methoxy indole in dry ether, 1-ethyl-methoxy indole-3-yl-glyoxyl chloride which was the crude product, propan-2-amine, two drops of triethylamine were in dry dichloromethane. The reaction mixture was washed with water and dried over Na₂SO₄ and concentrated in vacuo (Bacher et al., 2001). The residue was resolved in a methanol solution. Slow evaporatin over two week at room temperature gave light-yellow crystals suitable for X-ray analysis.

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. View of the title compound, with displacement ellipsoids drawn at the 40% probability level.

2-(1-Ethyl-5-methoxy-1H-indol-3-yl)-N-isopropyl-2-oxoacetamide top

Crystal data top

C₁₆H₂₀N₂O₃	F(000) = 1232
M_r = 288.34	D_x = 1.295 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 9914 reflections
a = 11.593 (3) Å	θ = 1.9–27.9°
b = 9.182 (2) Å	µ = 0.09 mm⁻¹
c = 27.796 (6) Å	T = 113 K
V = 2958.8 (11) Å³	Prism, colorless
Z = 8	0.30 × 0.24 × 0.10 mm

Data collection top

Rigaku Saturn CCD area-detector diffractometer	3527 independent reflections
Radiation source: rotating anode	3320 reflections with I > 2σ(I)
Multilayer monochromator	R_int = 0.053
Detector resolution: 14.63 pixels mm^-1	θ_max = 27.9°, θ_min = 1.5°
ω and ϕ scans	h = −14→15
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −12→9
T_min = 0.974, T_max = 0.991	l = −36→36
25486 measured 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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.133	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	w = 1/[σ²(F_o²) + (0.0661P)² + 0.8297P] where P = (F_o² + 2F_c²)/3
3527 reflections	(Δ/σ)_max = 0.001
204 parameters	Δρ_max = 0.32 e Å⁻³
39 restraints	Δρ_min = −0.28 e Å⁻³

Crystal data top

C₁₆H₂₀N₂O₃	V = 2958.8 (11) Å³
M_r = 288.34	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 11.593 (3) Å	µ = 0.09 mm⁻¹
b = 9.182 (2) Å	T = 113 K
c = 27.796 (6) Å	0.30 × 0.24 × 0.10 mm

Data collection top

Rigaku Saturn CCD area-detector diffractometer	3527 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	3320 reflections with I > 2σ(I)
T_min = 0.974, T_max = 0.991	R_int = 0.053
25486 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	39 restraints
wR(F²) = 0.133	H atoms treated by a mixture of independent and constrained refinement
S = 1.12	Δρ_max = 0.32 e Å⁻³
3527 reflections	Δρ_min = −0.28 e Å⁻³
204 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	Occ. (<1)
O1	0.47198 (9)	0.63365 (11)	0.45512 (3)	0.0265 (2)
O2	0.65875 (8)	0.73051 (10)	0.62010 (3)	0.0242 (2)
O3	0.64406 (8)	1.05760 (10)	0.68489 (3)	0.0233 (2)
N1	0.37396 (10)	1.06105 (12)	0.58694 (4)	0.0201 (2)
N2	0.75248 (11)	0.85420 (14)	0.69650 (4)	0.0247 (3)
C1	0.38287 (11)	0.95977 (14)	0.54960 (4)	0.0188 (3)
C2	0.31491 (12)	0.94441 (14)	0.50881 (4)	0.0208 (3)
H2A	0.2511	1.0070	0.5031	0.025*
C3	0.34338 (11)	0.83450 (15)	0.47660 (5)	0.0210 (3)
H3A	0.2987	0.8211	0.4483	0.025*
C4	0.43820 (11)	0.74299 (14)	0.48577 (4)	0.0200 (3)
C5	0.50502 (11)	0.75732 (14)	0.52708 (4)	0.0198 (3)
H5A	0.5681	0.6938	0.5330	0.024*
C6	0.47675 (11)	0.86775 (14)	0.55956 (4)	0.0177 (3)
C7	0.52557 (11)	0.91743 (14)	0.60485 (4)	0.0185 (3)
C8	0.45861 (11)	1.03582 (14)	0.61905 (4)	0.0191 (3)
H8A	0.4710	1.0911	0.6475	0.023*
C9	0.27776 (12)	1.16154 (15)	0.59397 (5)	0.0244 (3)
H9A	0.2564	1.2055	0.5627	0.029*
H9B	0.3020	1.2411	0.6158	0.029*
C10	0.17353 (13)	1.08439 (16)	0.61518 (5)	0.0284 (3)
H10A	0.1105	1.1544	0.6194	0.043*
H10B	0.1941	1.0425	0.6464	0.043*
H10C	0.1487	1.0066	0.5934	0.043*
C11	0.40229 (13)	0.60947 (16)	0.41358 (5)	0.0261 (3)
H11A	0.4349	0.5295	0.3946	0.039*
H11B	0.4003	0.6982	0.3940	0.039*
H11C	0.3238	0.5841	0.4236	0.039*
C12	0.61865 (11)	0.85066 (14)	0.63061 (4)	0.0180 (3)
C13	0.67303 (11)	0.93253 (14)	0.67372 (4)	0.0189 (3)
C15	0.9362 (6)	0.9639 (14)	0.7211 (3)	0.0447 (16)	0.61 (3)
H15A	0.9270	1.0323	0.6943	0.067*	0.61 (3)
H15B	0.9831	0.8809	0.7106	0.067*	0.61 (3)
H15C	0.9746	1.0132	0.7479	0.067*	0.61 (3)
C14	0.81996 (14)	0.91109 (16)	0.73695 (5)	0.0291 (3)	0.61 (3)
H14A	0.7777	0.9993	0.7485	0.035*	0.61 (3)
C15'	0.9489 (8)	0.911 (2)	0.7214 (5)	0.048 (3)	0.39 (3)
H15D	0.9596	0.9779	0.6943	0.072*	0.39 (3)
H15E	0.9712	0.8122	0.7115	0.072*	0.39 (3)
H15F	0.9971	0.9418	0.7485	0.072*	0.39 (3)
C14'	0.81996 (14)	0.91109 (16)	0.73695 (5)	0.0291 (3)	0.39 (3)
H14B	0.7935	1.0102	0.7470	0.035*	0.39 (3)
C16	0.81764 (17)	0.8043 (2)	0.77817 (5)	0.0408 (4)
H16A	0.7405	0.7968	0.7907	0.049*
H16B	0.8425	0.7108	0.7667	0.049*
H16C	0.8685	0.8368	0.8027	0.049*
H2B	0.7703 (15)	0.765 (2)	0.6858 (6)	0.031 (5)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0291 (5)	0.0292 (5)	0.0212 (5)	0.0041 (4)	−0.0062 (4)	−0.0094 (4)
O2	0.0260 (5)	0.0223 (5)	0.0243 (5)	0.0028 (4)	−0.0032 (4)	−0.0065 (4)
O3	0.0265 (5)	0.0199 (5)	0.0234 (5)	−0.0003 (4)	−0.0028 (4)	−0.0050 (4)
N1	0.0251 (6)	0.0172 (5)	0.0181 (5)	0.0007 (4)	−0.0016 (4)	−0.0008 (4)
N2	0.0303 (6)	0.0212 (6)	0.0227 (5)	0.0025 (5)	−0.0089 (5)	−0.0065 (5)
C1	0.0229 (6)	0.0165 (6)	0.0171 (6)	−0.0022 (5)	0.0016 (5)	0.0011 (5)
C2	0.0235 (7)	0.0206 (6)	0.0183 (6)	0.0003 (5)	−0.0015 (5)	0.0026 (5)
C3	0.0232 (7)	0.0220 (6)	0.0178 (6)	−0.0030 (5)	−0.0025 (5)	0.0010 (5)
C4	0.0228 (6)	0.0196 (6)	0.0176 (6)	−0.0027 (5)	0.0007 (5)	−0.0018 (5)
C5	0.0199 (6)	0.0206 (6)	0.0189 (6)	−0.0011 (5)	−0.0002 (5)	−0.0005 (5)
C6	0.0188 (6)	0.0181 (6)	0.0162 (5)	−0.0046 (5)	0.0009 (4)	0.0006 (5)
C7	0.0208 (6)	0.0188 (6)	0.0157 (5)	−0.0042 (5)	0.0014 (4)	−0.0003 (5)
C8	0.0226 (6)	0.0181 (6)	0.0165 (6)	−0.0031 (5)	0.0000 (5)	0.0002 (5)
C9	0.0318 (7)	0.0185 (6)	0.0228 (6)	0.0059 (5)	−0.0032 (5)	−0.0005 (5)
C10	0.0274 (7)	0.0273 (7)	0.0304 (7)	0.0082 (6)	−0.0016 (6)	−0.0013 (6)
C11	0.0308 (7)	0.0286 (7)	0.0189 (6)	−0.0015 (6)	−0.0052 (5)	−0.0062 (5)
C12	0.0189 (6)	0.0197 (6)	0.0154 (5)	−0.0038 (5)	0.0024 (4)	−0.0011 (4)
C13	0.0204 (6)	0.0208 (6)	0.0154 (5)	−0.0035 (5)	0.0015 (5)	−0.0013 (4)
C15	0.053 (2)	0.049 (4)	0.0325 (17)	−0.027 (2)	−0.0132 (15)	0.002 (2)
C14	0.0383 (8)	0.0248 (7)	0.0240 (7)	0.0002 (6)	−0.0138 (6)	−0.0066 (5)
C15'	0.051 (4)	0.059 (6)	0.035 (3)	−0.032 (4)	−0.009 (3)	−0.002 (4)
C14'	0.0383 (8)	0.0248 (7)	0.0240 (7)	0.0002 (6)	−0.0138 (6)	−0.0066 (5)
C16	0.0567 (11)	0.0436 (10)	0.0222 (7)	−0.0091 (8)	−0.0086 (7)	−0.0035 (6)

Geometric parameters (Å, º) top

O1—C4	1.3739 (15)	C9—C10	1.520 (2)
O1—C11	1.4264 (16)	C9—H9A	0.9900
O2—C12	1.2323 (16)	C9—H9B	0.9900
O3—C13	1.2361 (16)	C10—H10A	0.9800
N1—C8	1.3465 (16)	C10—H10B	0.9800
N1—C1	1.3974 (16)	C10—H10C	0.9800
N1—C9	1.4606 (17)	C11—H11A	0.9800
N2—C13	1.3291 (18)	C11—H11B	0.9800
N2—C14	1.4659 (17)	C11—H11C	0.9800
N2—H2B	0.894 (19)	C12—C13	1.5487 (17)
C1—C2	1.3879 (18)	C15—C14	1.499 (5)
C1—C6	1.4053 (18)	C15—H15A	0.9800
C2—C3	1.3888 (18)	C15—H15B	0.9800
C2—H2A	0.9500	C15—H15C	0.9800
C3—C4	1.4069 (19)	C14—C16	1.508 (2)
C3—H3A	0.9500	C14—H14A	1.0000
C4—C5	1.3913 (18)	C15'—H15D	0.9800
C5—C6	1.3966 (17)	C15'—H15E	0.9800
C5—H5A	0.9500	C15'—H15F	0.9800
C6—C7	1.4537 (17)	C16—H16A	0.9632
C7—C8	1.3928 (18)	C16—H16B	0.9595
C7—C12	1.4329 (18)	C16—H16C	0.9502
C8—H8A	0.9500

C4—O1—C11	117.02 (11)	C9—C10—H10B	109.5
C8—N1—C1	108.90 (11)	H10A—C10—H10B	109.5
C8—N1—C9	125.21 (11)	C9—C10—H10C	109.5
C1—N1—C9	125.18 (11)	H10A—C10—H10C	109.5
C13—N2—C14	122.84 (12)	H10B—C10—H10C	109.5
C13—N2—H2B	119.8 (12)	O1—C11—H11A	109.5
C14—N2—H2B	117.2 (12)	O1—C11—H11B	109.5
C2—C1—N1	129.23 (12)	H11A—C11—H11B	109.5
C2—C1—C6	122.64 (12)	O1—C11—H11C	109.5
N1—C1—C6	108.12 (11)	H11A—C11—H11C	109.5
C1—C2—C3	117.75 (12)	H11B—C11—H11C	109.5
C1—C2—H2A	121.1	O2—C12—C7	123.27 (12)
C3—C2—H2A	121.1	O2—C12—C13	117.68 (11)
C2—C3—C4	120.19 (12)	C7—C12—C13	119.05 (11)
C2—C3—H3A	119.9	O3—C13—N2	124.85 (12)
C4—C3—H3A	119.9	O3—C13—C12	122.32 (12)
O1—C4—C5	114.98 (12)	N2—C13—C12	112.83 (11)
O1—C4—C3	123.14 (11)	C14—C15—H15A	109.5
C5—C4—C3	121.88 (12)	C14—C15—H15B	109.5
C4—C5—C6	118.12 (12)	H15A—C15—H15B	109.5
C4—C5—H5A	120.9	C14—C15—H15C	109.5
C6—C5—H5A	120.9	H15A—C15—H15C	109.5
C5—C6—C1	119.40 (12)	H15B—C15—H15C	109.5
C5—C6—C7	134.12 (12)	N2—C14—C15	111.7 (3)
C1—C6—C7	106.47 (11)	N2—C14—C16	109.97 (12)
C8—C7—C12	127.74 (11)	C15—C14—C16	116.8 (4)
C8—C7—C6	105.86 (11)	N2—C14—H14A	105.9
C12—C7—C6	126.28 (12)	C15—C14—H14A	105.9
N1—C8—C7	110.65 (11)	C16—C14—H14A	105.9
N1—C8—H8A	124.7	H15D—C15'—H15E	109.5
C7—C8—H8A	124.7	H15D—C15'—H15F	109.5
N1—C9—C10	111.38 (11)	H15E—C15'—H15F	109.5
N1—C9—H9A	109.4	C14—C16—H16A	109.8
C10—C9—H9A	109.4	C14—C16—H16B	109.0
N1—C9—H9B	109.4	H16A—C16—H16B	109.6
C10—C9—H9B	109.4	C14—C16—H16C	109.3
H9A—C9—H9B	108.0	H16A—C16—H16C	109.7
C9—C10—H10A	109.5	H16B—C16—H16C	109.5

C8—N1—C1—C2	−179.77 (13)	C5—C6—C7—C12	−5.2 (2)
C9—N1—C1—C2	9.5 (2)	C1—C6—C7—C12	175.99 (12)
C8—N1—C1—C6	0.47 (14)	C1—N1—C8—C7	−0.64 (15)
C9—N1—C1—C6	−170.26 (12)	C9—N1—C8—C7	170.09 (12)
N1—C1—C2—C3	179.21 (12)	C12—C7—C8—N1	−175.62 (12)
C6—C1—C2—C3	−1.05 (19)	C6—C7—C8—N1	0.54 (14)
C1—C2—C3—C4	0.07 (19)	C8—N1—C9—C10	−92.41 (15)
C11—O1—C4—C5	176.62 (12)	C1—N1—C9—C10	76.84 (16)
C11—O1—C4—C3	−3.38 (19)	C8—C7—C12—O2	165.58 (13)
C2—C3—C4—O1	−179.06 (12)	C6—C7—C12—O2	−9.8 (2)
C2—C3—C4—C5	0.9 (2)	C8—C7—C12—C13	−14.81 (19)
O1—C4—C5—C6	179.04 (11)	C6—C7—C12—C13	169.78 (11)
C3—C4—C5—C6	−0.96 (19)	C14—N2—C13—O3	−3.0 (2)
C4—C5—C6—C1	−0.01 (18)	C14—N2—C13—C12	176.90 (12)
C4—C5—C6—C7	−178.74 (13)	O2—C12—C13—O3	174.90 (12)
C2—C1—C6—C5	1.04 (19)	C7—C12—C13—O3	−4.74 (18)
N1—C1—C6—C5	−179.18 (11)	O2—C12—C13—N2	−4.97 (17)
C2—C1—C6—C7	−179.92 (12)	C7—C12—C13—N2	175.39 (12)
N1—C1—C6—C7	−0.13 (14)	C13—N2—C14—C15	−97.9 (6)
C5—C6—C7—C8	178.61 (14)	C13—N2—C14—C16	130.80 (15)
C1—C6—C7—C8	−0.23 (13)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···O2ⁱ	0.95	2.54	3.4874 (17)	172
N2—H2B···O3ⁱⁱ	0.894 (19)	2.149 (19)	2.9933 (17)	157.2 (16)
Cg1···Cg2ⁱⁱⁱ			3.693 (9)
Cg2···Cg2ⁱⁱⁱ			3.577 (9)

Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) −x+3/2, y−1/2, z; (iii) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	C₁₆H₂₀N₂O₃
M_r	288.34
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	113
a, b, c (Å)	11.593 (3), 9.182 (2), 27.796 (6)
V (Å³)	2958.8 (11)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.30 × 0.24 × 0.10

Data collection
Diffractometer	Rigaku Saturn CCD area-detector diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.974, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	25486, 3527, 3320
R_int	0.053
(sin θ/λ)_max (Å⁻¹)	0.658

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.133, 1.12
No. of reflections	3527
No. of parameters	204
No. of restraints	39
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.32, −0.28

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···O2ⁱ	0.95	2.54	3.4874 (17)	172
N2—H2B···O3ⁱⁱ	0.894 (19)	2.149 (19)	2.9933 (17)	157.2 (16)
Cg1···Cg2ⁱⁱⁱ	.	.	3.693 (9)	.
Cg2···Cg2ⁱⁱⁱ	.	.	3.577 (9)	.

Symmetry codes: (i) x−1/2, −y+3/2, −z+1; (ii) −x+3/2, y−1/2, z; (iii) −x+1, −y+1, −z.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. 30873363), the Program of the Science Foundation of Tianjin (08JCYBJC070000) and the Major Program of the Science Foundation of Tianjin (09ZCKFSH01700).

References

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