(Z)-3-(1H-Indol-3-yl)-2-(3,4,5-tri­methoxy­phen­yl)acrylonitrile

Penthala, N.R.; Parkin, S.; Crooks, P.A.

doi:10.1107/S1600536812005855

organic compounds

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ISSN: 2056-9890

Volume 68| Part 3| March 2012| Page o729

doi:10.1107/S1600536812005855

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(Z)-3-(1H-Indol-3-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile

Narsimha Reddy Penthala,^a Sean Parkin ^b and Peter A. Crooks ^a ^*

^aDepartment of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, and ^bDepartment of Chemistry, University of Kentucky, Lexington, KY 40506, USA
^*Correspondence e-mail: pacrooks@uams.edu

(Received 4 November 2011; accepted 9 February 2012; online 17 February 2012)

In the title compound, C₂₀H₁₈N₂O₃, the C=C bond of the acrylonitrile group that links the indole and the 3,4,5-trimethoxyphenyl rings has Z geometry, with dihedral angles between the plane of the acrylonitrile unit and the planes of the benzene and indole ring systems of 21.96 (5) and 38.94 (7)°, respectively. The acrylonitrile group is planar (r.m.s. deviation from planarity = 0.037 Å). Molecules are linked into head-to-tail chains that propagate along the b-axis direction by bifurcated N—H⋯O intermolecular hydrogen bonds, which form an R₁²(5) motif between the indole NH group and the two methoxy O atoms furthest from the nitrile group.

Related literature

For biological activity of similar acrylonitriles, see: Naruto et al. (1983 ); Ohsumi et al. (1998 ); Saczewski et al. (2004 ). For the molecular structures of (E)-3-(benzo[b]thiophen-2-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile and (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,4-dimethoxyphenyl)acrylonitrile, see: Sonar et al. (2007 ). For the structure of (Z)-4-[3-(2,5-dioxoimidazolidin-4-ylidenemethyl)-1H-indol-1-ylmethyl]benzonitrile, see: Penthala et al. (2008 ).

Experimental

Crystal data

C₂₀H₁₈N₂O₃
M_r = 334.36
Monoclinic, P 2₁ /c
a = 11.3384 (4) Å
b = 21.1383 (8) Å
c = 6.9570 (3) Å
β = 93.610 (2)°
V = 1664.11 (11) Å³
Z = 4
Cu Kα radiation
μ = 0.74 mm⁻¹
T = 90 K
0.24 × 0.07 × 0.02 mm

Data collection

Bruker X8 Proteum diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ) T_min = 0.843, T_max = 0.929
20812 measured reflections
2979 independent reflections
2679 reflections with I > 2σ(I)
R_int = 0.053

Refinement

R[F² > 2σ(F²)] = 0.037
wR(F²) = 0.097
S = 1.07
2979 reflections
233 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O2ⁱ	0.851 (18)	2.075 (18)	2.8635 (15)	153.8 (16)
N1—H1N⋯O3ⁱ	0.851 (18)	2.301 (17)	2.9476 (15)	133.0 (15)
Symmetry code: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 and local procedures.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812005855/nk2125sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812005855/nk2125Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812005855/nk2125Isup3.cml

checkCIF report

Comment top

A number of 2,3-diarylacrylonitrile analogs have been found to possess interesting biological properties such as spasmolytic (Naruto et al., 1983), and cytotoxic activities (Ohsumi et al., 1998 and Saczewski et al., 2004). Previously, we have reported on the crystallographic data of benzothiophene acrylonitrile analogs (Sonar et al., 2007). In continuation of the synthesis of structurally related analogs and to compare the structure–activity relationships of different substituted acrylonitrile analogs, we have now prepared the title compound, (I), by the reaction of indole-3-carbaldehyde with (3,4,5-trimethoxyphenyl)acetonitrile in methanolic sodium methoxide at reflux temperature. Recrystallization from methanol afforded yellow needles of (I) that were suitable for X-ray analysis. The X-ray studies revealed that the title compound is the Z isomer. The olefinic bond linking the indole ring and the 3,4,5-trimethoxyphenyl units has a planar atomic arrangement. The r.m.s. deviation from the mean plane passing through atoms of C1–C2–C3–C8–N1 is 0.0133 Å. The acrylonitrile group is planar (r.m.s. deviation from planarity is 0.037 Å). In the trimethoxyphenyl group, one methyl is essentially in the plane of the benzene ring and the three O atoms [deviation = 0.0253 (18) Å]. The middle methyl has the largest [deviation = 1.0600 (17) Å], while the methyl that is on the same side as the nitrile group is in between [0.3788 (19)Å out of plane]. Significant deviations from the ideal bond-angle geometry around the Csp² atoms of the double bond are observed. The C1–C2–C3 and C1–C2–C9, C4–C3–C2 and C8–C3–C2 bond angles [105.88 (12)°, 127.93 (13)°, 134.18 (13)°, 106.90 (12)°, respectively] are distorted owing to steric hindrance around the double bond linking the two ring systems. Neither the indole ring nor the benzene ring of the 3,4,5-trimethoxyphenyl group is coplanar with the vinyl double bond, making dihedral angles of 38.94 (7)° and 21.96 (5)° respectively. Molecules are linked into head-to-tail chains that propagate along the b axis direction by bifurcated N—H···O intermolecular hydrogen bonds that form an R²₁(5) motif between the indole NH and the two methoxy O atoms furthest from the nitrile group, as shown in Figure 2.

Related literature top

For biological activity of similar acrylonitriles, see: Naruto et al. (1983); Ohsumi et al. (1998); Saczewski et al. (2004). For the molecular structures of (E)-3-(benzo[b]thiophen-2-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile and (Z)-3-(benzo[b]thiophen-2-yl)-2- (3,4-dimethoxyphenyl)acrylonitrile, see: Sonar et al. (2007). For the structure of (Z)-4-[3-(2,5-dioxoimidazolidin-4-ylidenemethyl) -1H-indol-1-ylmethyl]benzonitrile, see: Penthala et al. (2008).

Experimental top

A mixture of indole-3-carbaldehyde (0.3 g, 2.06 mmol), and 2-(3,4,5-trimethoxyphenyl)acetonitrile (0.45 g, 2.17 mmol) were refluxed in methanolic 5% sodium methoxide solution for 5 hrs. The reaction mixture was cooled to room temperature and added to ice–cold water to afford a yellow crude solid, which was collected by filtration, washed with a 1:1 mixture of cold water and methanol, and suction–dried to afford the crude product. Crystallization during slow evaporation of methanol gave a yellow crystalline product of (Z)-3-(1H-indol-3-yl)-2- (3,4,5-trimethoxyphenyl)acrylonitrile that was suitable for X-ray crystallographic analysis. ¹H NMR (CDCl₃): δ 3.91 (s, 3H), 3.93 (s, 6H), 6.89 (s, 2H), 7.26–7.35 (m, 2H), 7.47–7.50 (d, 1H), 7.79 (s, 1H), 7.81 (s, 1H), 8.45–8.46 (d, 1H), 8.91 (bs, 1H, NH); ¹³C NMR (CDCl₃): δ 56.57, 61.28, 102.92, 105.11, 106.03, 111.83, 112.91, 121.19, 121.75, 125.77, 127.47, 129.27, 130.94, 132.38, 138.19, 153.76.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: APEX2 (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and local procedures.

Figures top

	Fig. 1. The asymmetric unit of (I). Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Bifurcated N–H···O bonding interactions (dashed lines) in the crystal structure of (I)

(Z)-3-(1H-Indol-3-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile top

Crystal data top

C₂₀H₁₈N₂O₃	F(000) = 704
M_r = 334.36	D_x = 1.335 Mg m⁻³
Monoclinic, P2₁/c	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybc	Cell parameters from 9970 reflections
a = 11.3384 (4) Å	θ = 3.9–68.1°
b = 21.1383 (8) Å	µ = 0.74 mm⁻¹
c = 6.9570 (3) Å	T = 90 K
β = 93.610 (2)°	Lath, yellow
V = 1664.11 (11) Å³	0.24 × 0.07 × 0.02 mm
Z = 4

Data collection top

Bruker X8 Proteum diffractometer	2979 independent reflections
Radiation source: fine-focus rotating anode	2679 reflections with I > 2σ(I)
Graded multilayer optics monochromator	R_int = 0.053
Detector resolution: 5.6 pixels mm^-1	θ_max = 68.1°, θ_min = 3.9°
ϕ and ω scans	h = −13→13
Absorption correction: multi-scan (SADABS in APEX2; Bruker, 2006)	k = −25→25
T_min = 0.843, T_max = 0.929	l = −7→8
20812 measured reflections

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)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.097	w = 1/[σ²(F_o²) + (0.0417P)² + 0.7731P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max < 0.001
2979 reflections	Δρ_max = 0.26 e Å⁻³
233 parameters	Δρ_min = −0.20 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0016 (3)

Crystal data top

C₂₀H₁₈N₂O₃	V = 1664.11 (11) Å³
M_r = 334.36	Z = 4
Monoclinic, P2₁/c	Cu Kα radiation
a = 11.3384 (4) Å	µ = 0.74 mm⁻¹
b = 21.1383 (8) Å	T = 90 K
c = 6.9570 (3) Å	0.24 × 0.07 × 0.02 mm
β = 93.610 (2)°

Data collection top

Bruker X8 Proteum diffractometer	2979 independent reflections
Absorption correction: multi-scan (SADABS in APEX2; Bruker, 2006)	2679 reflections with I > 2σ(I)
T_min = 0.843, T_max = 0.929	R_int = 0.053
20812 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	0 restraints
wR(F²) = 0.097	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	Δρ_max = 0.26 e Å⁻³
2979 reflections	Δρ_min = −0.20 e Å⁻³
233 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-value wR and goodness of fit S are based on F². Conventional R-values R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-values based on F² are statistically about twice as large as those based on F, and R-values 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	0.29609 (11)	0.42543 (6)	0.78546 (16)	0.0203 (3)
H1N	0.2929 (15)	0.4617 (8)	0.732 (2)	0.024*
N2	0.68309 (12)	0.37056 (6)	0.89979 (17)	0.0251 (3)
O1	0.91232 (9)	0.14011 (4)	1.03760 (14)	0.0220 (2)
O2	0.79293 (9)	0.03501 (4)	0.91759 (13)	0.0202 (2)
O3	0.56732 (8)	0.03817 (4)	0.81372 (14)	0.0203 (2)
C1	0.38533 (13)	0.38300 (6)	0.77536 (19)	0.0195 (3)
H1	0.4520	0.3883	0.7009	0.023*
C2	0.36515 (12)	0.33101 (6)	0.88911 (18)	0.0177 (3)
C3	0.25524 (12)	0.34334 (6)	0.97547 (18)	0.0172 (3)
C4	0.18967 (13)	0.31113 (6)	1.1088 (2)	0.0206 (3)
H4	0.2151	0.2712	1.1585	0.025*
C5	0.08734 (14)	0.33867 (7)	1.1662 (2)	0.0253 (3)
H5	0.0426	0.3174	1.2574	0.030*
C6	0.04772 (14)	0.39732 (7)	1.0932 (2)	0.0266 (3)
H6	−0.0241	0.4145	1.1335	0.032*
C7	0.11116 (13)	0.43046 (7)	0.9640 (2)	0.0225 (3)
H7	0.0850	0.4704	0.9153	0.027*
C8	0.21522 (13)	0.40300 (6)	0.90769 (19)	0.0188 (3)
C9	0.43611 (12)	0.27458 (6)	0.91389 (18)	0.0175 (3)
H9	0.3947	0.2367	0.9389	0.021*
C10	0.55447 (13)	0.26926 (6)	0.90571 (18)	0.0170 (3)
C11	0.61787 (12)	0.20801 (6)	0.91199 (18)	0.0166 (3)
C12	0.73704 (12)	0.20546 (6)	0.97301 (18)	0.0173 (3)
H12	0.7781	0.2431	1.0103	0.021*
C13	0.79597 (12)	0.14770 (6)	0.97940 (18)	0.0173 (3)
C14	0.73641 (12)	0.09257 (6)	0.92416 (18)	0.0166 (3)
C15	0.61699 (12)	0.09519 (6)	0.86363 (18)	0.0166 (3)
C16	0.55781 (12)	0.15264 (6)	0.85555 (18)	0.0163 (3)
H16	0.4768	0.1544	0.8118	0.020*
C17	0.62542 (13)	0.32580 (6)	0.89881 (18)	0.0185 (3)
C18	0.96763 (14)	0.19066 (7)	1.1428 (2)	0.0263 (3)
H18A	0.9721	0.2277	1.0590	0.039*
H18B	1.0476	0.1780	1.1892	0.039*
H18C	0.9214	0.2012	1.2529	0.039*
C19	0.84428 (13)	0.01136 (7)	1.0993 (2)	0.0242 (3)
H19A	0.9256	0.0269	1.1196	0.036*
H19B	0.8445	−0.0350	1.0971	0.036*
H19C	0.7976	0.0262	1.2042	0.036*
C20	0.44638 (13)	0.03775 (7)	0.7438 (2)	0.0227 (3)
H20A	0.3972	0.0538	0.8440	0.034*
H20B	0.4225	−0.0056	0.7100	0.034*
H20C	0.4363	0.0648	0.6295	0.034*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0269 (7)	0.0156 (6)	0.0183 (6)	0.0011 (5)	−0.0004 (5)	0.0033 (5)
N2	0.0311 (7)	0.0229 (7)	0.0218 (6)	−0.0038 (5)	0.0048 (5)	−0.0011 (5)
O1	0.0174 (5)	0.0210 (5)	0.0270 (5)	−0.0010 (4)	−0.0031 (4)	−0.0036 (4)
O2	0.0221 (5)	0.0176 (5)	0.0202 (5)	0.0035 (4)	−0.0040 (4)	−0.0021 (4)
O3	0.0198 (5)	0.0160 (5)	0.0245 (5)	−0.0015 (4)	−0.0042 (4)	−0.0019 (4)
C1	0.0237 (8)	0.0196 (7)	0.0153 (6)	0.0002 (6)	0.0008 (6)	0.0000 (5)
C2	0.0222 (7)	0.0176 (7)	0.0131 (6)	−0.0018 (5)	−0.0017 (5)	−0.0013 (5)
C3	0.0196 (7)	0.0160 (7)	0.0153 (6)	−0.0018 (5)	−0.0030 (5)	−0.0031 (5)
C4	0.0240 (8)	0.0172 (7)	0.0205 (7)	−0.0027 (6)	−0.0007 (6)	−0.0008 (5)
C5	0.0271 (8)	0.0232 (7)	0.0262 (8)	−0.0059 (6)	0.0074 (6)	−0.0054 (6)
C6	0.0227 (8)	0.0252 (8)	0.0320 (8)	−0.0002 (6)	0.0034 (6)	−0.0095 (6)
C7	0.0230 (8)	0.0181 (7)	0.0257 (7)	0.0025 (6)	−0.0046 (6)	−0.0054 (5)
C8	0.0223 (7)	0.0169 (7)	0.0167 (6)	−0.0014 (5)	−0.0030 (6)	−0.0027 (5)
C9	0.0241 (8)	0.0166 (7)	0.0118 (6)	−0.0017 (5)	0.0006 (5)	−0.0002 (5)
C10	0.0238 (8)	0.0174 (7)	0.0098 (6)	−0.0011 (5)	0.0007 (5)	0.0003 (5)
C11	0.0225 (7)	0.0182 (7)	0.0095 (6)	0.0004 (5)	0.0035 (5)	0.0014 (5)
C12	0.0214 (7)	0.0173 (7)	0.0133 (6)	−0.0028 (5)	0.0014 (5)	−0.0006 (5)
C13	0.0184 (7)	0.0220 (7)	0.0116 (6)	−0.0010 (5)	0.0005 (5)	0.0007 (5)
C14	0.0206 (7)	0.0166 (7)	0.0125 (6)	0.0020 (5)	0.0005 (5)	−0.0003 (5)
C15	0.0218 (7)	0.0169 (7)	0.0110 (6)	−0.0023 (5)	0.0007 (5)	−0.0004 (5)
C16	0.0178 (7)	0.0195 (7)	0.0115 (6)	0.0011 (5)	−0.0001 (5)	0.0010 (5)
C17	0.0230 (7)	0.0202 (7)	0.0124 (6)	0.0035 (6)	0.0024 (5)	−0.0006 (5)
C18	0.0250 (8)	0.0240 (8)	0.0288 (8)	−0.0042 (6)	−0.0060 (6)	−0.0033 (6)
C19	0.0243 (8)	0.0216 (7)	0.0257 (7)	0.0022 (6)	−0.0062 (6)	0.0033 (6)
C20	0.0201 (8)	0.0210 (7)	0.0261 (7)	−0.0018 (6)	−0.0050 (6)	−0.0013 (6)

Geometric parameters (Å, º) top

N1—C1	1.3572 (19)	C7—H7	0.9500
N1—C8	1.3737 (19)	C9—C10	1.351 (2)
N1—H1N	0.851 (18)	C9—H9	0.9500
N2—C17	1.1499 (19)	C10—C17	1.4433 (19)
O1—C13	1.3649 (17)	C10—C11	1.4801 (18)
O1—C18	1.4188 (17)	C11—C12	1.392 (2)
O2—C14	1.3773 (16)	C11—C16	1.3980 (19)
O2—C19	1.4472 (17)	C12—C13	1.3910 (19)
O3—C15	1.3661 (16)	C12—H12	0.9500
O3—C20	1.4257 (17)	C13—C14	1.3890 (19)
C1—C2	1.3818 (19)	C14—C15	1.394 (2)
C1—H1	0.9500	C15—C16	1.3868 (19)
C2—C3	1.4409 (19)	C16—H16	0.9500
C2—C9	1.4430 (19)	C18—H18A	0.9800
C3—C4	1.4011 (19)	C18—H18B	0.9800
C3—C8	1.4113 (19)	C18—H18C	0.9800
C4—C5	1.380 (2)	C19—H19A	0.9800
C4—H4	0.9500	C19—H19B	0.9800
C5—C6	1.403 (2)	C19—H19C	0.9800
C5—H5	0.9500	C20—H20A	0.9800
C6—C7	1.377 (2)	C20—H20B	0.9800
C6—H6	0.9500	C20—H20C	0.9800
C7—C8	1.393 (2)

C1—N1—C8	109.44 (12)	C12—C11—C10	120.23 (12)
C1—N1—H1N	125.7 (11)	C16—C11—C10	119.80 (13)
C8—N1—H1N	124.7 (11)	C13—C12—C11	119.93 (12)
C13—O1—C18	116.87 (11)	C13—C12—H12	120.0
C14—O2—C19	116.02 (10)	C11—C12—H12	120.0
C15—O3—C20	117.67 (11)	O1—C13—C14	115.30 (12)
N1—C1—C2	110.19 (12)	O1—C13—C12	124.47 (12)
N1—C1—H1	124.9	C14—C13—C12	120.23 (13)
C2—C1—H1	124.9	O2—C14—C13	122.10 (12)
C1—C2—C3	105.88 (12)	O2—C14—C15	118.06 (12)
C1—C2—C9	127.93 (13)	C13—C14—C15	119.76 (12)
C3—C2—C9	126.16 (12)	O3—C15—C16	124.87 (13)
C4—C3—C8	118.85 (13)	O3—C15—C14	114.77 (11)
C4—C3—C2	134.18 (13)	C16—C15—C14	120.36 (12)
C8—C3—C2	106.90 (12)	C15—C16—C11	119.73 (13)
C5—C4—C3	118.52 (13)	C15—C16—H16	120.1
C5—C4—H4	120.7	C11—C16—H16	120.1
C3—C4—H4	120.7	N2—C17—C10	177.68 (14)
C4—C5—C6	121.61 (13)	O1—C18—H18A	109.5
C4—C5—H5	119.2	O1—C18—H18B	109.5
C6—C5—H5	119.2	H18A—C18—H18B	109.5
C7—C6—C5	121.15 (14)	O1—C18—H18C	109.5
C7—C6—H6	119.4	H18A—C18—H18C	109.5
C5—C6—H6	119.4	H18B—C18—H18C	109.5
C6—C7—C8	117.25 (13)	O2—C19—H19A	109.5
C6—C7—H7	121.4	O2—C19—H19B	109.5
C8—C7—H7	121.4	H19A—C19—H19B	109.5
N1—C8—C7	129.82 (13)	O2—C19—H19C	109.5
N1—C8—C3	107.59 (12)	H19A—C19—H19C	109.5
C7—C8—C3	122.59 (13)	H19B—C19—H19C	109.5
C10—C9—C2	127.70 (13)	O3—C20—H20A	109.5
C10—C9—H9	116.1	O3—C20—H20B	109.5
C2—C9—H9	116.1	H20A—C20—H20B	109.5
C9—C10—C17	119.30 (12)	O3—C20—H20C	109.5
C9—C10—C11	123.60 (12)	H20A—C20—H20C	109.5
C17—C10—C11	117.04 (12)	H20B—C20—H20C	109.5
C12—C11—C16	119.97 (12)

C8—N1—C1—C2	0.67 (16)	C9—C10—C11—C16	23.89 (19)
N1—C1—C2—C3	−0.36 (15)	C17—C10—C11—C16	−158.85 (12)
N1—C1—C2—C9	177.84 (13)	C16—C11—C12—C13	−0.58 (18)
C1—C2—C3—C4	−176.92 (15)	C10—C11—C12—C13	179.70 (11)
C9—C2—C3—C4	4.8 (2)	C18—O1—C13—C14	−163.42 (12)
C1—C2—C3—C8	−0.07 (15)	C18—O1—C13—C12	16.64 (18)
C9—C2—C3—C8	−178.31 (13)	C11—C12—C13—O1	−179.74 (11)
C8—C3—C4—C5	1.0 (2)	C11—C12—C13—C14	0.32 (19)
C2—C3—C4—C5	177.59 (14)	C19—O2—C14—C13	62.90 (16)
C3—C4—C5—C6	0.6 (2)	C19—O2—C14—C15	−120.39 (13)
C4—C5—C6—C7	−1.5 (2)	O1—C13—C14—O2	−3.80 (18)
C5—C6—C7—C8	0.7 (2)	C12—C13—C14—O2	176.14 (11)
C1—N1—C8—C7	179.00 (14)	O1—C13—C14—C15	179.55 (11)
C1—N1—C8—C3	−0.69 (15)	C12—C13—C14—C15	−0.51 (19)
C6—C7—C8—N1	−178.69 (14)	C20—O3—C15—C16	1.54 (18)
C6—C7—C8—C3	1.0 (2)	C20—O3—C15—C14	−177.79 (11)
C4—C3—C8—N1	177.88 (12)	O2—C14—C15—O3	3.54 (17)
C2—C3—C8—N1	0.46 (15)	C13—C14—C15—O3	−179.67 (11)
C4—C3—C8—C7	−1.8 (2)	O2—C14—C15—C16	−175.82 (11)
C2—C3—C8—C7	−179.26 (13)	C13—C14—C15—C16	0.97 (19)
C1—C2—C9—C10	31.1 (2)	O3—C15—C16—C11	179.48 (11)
C3—C2—C9—C10	−151.04 (14)	C14—C15—C16—C11	−1.22 (18)
C2—C9—C10—C17	9.7 (2)	C12—C11—C16—C15	1.03 (18)
C2—C9—C10—C11	−173.07 (12)	C10—C11—C16—C15	−179.25 (11)
C9—C10—C11—C12	−156.39 (13)	C9—C10—C17—N2	103 (4)
C17—C10—C11—C12	20.87 (17)	C11—C10—C17—N2	−74 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.851 (18)	2.075 (18)	2.8635 (15)	153.8 (16)
N1—H1N···O3ⁱ	0.851 (18)	2.301 (17)	2.9476 (15)	133.0 (15)

Symmetry code: (i) −x+1, y+1/2, −z+3/2.

Experimental details

Crystal data
Chemical formula	C₂₀H₁₈N₂O₃
M_r	334.36
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	90
a, b, c (Å)	11.3384 (4), 21.1383 (8), 6.9570 (3)
β (°)	93.610 (2)
V (Å³)	1664.11 (11)
Z	4
Radiation type	Cu Kα
µ (mm⁻¹)	0.74
Crystal size (mm)	0.24 × 0.07 × 0.02

Data collection
Diffractometer	Bruker X8 Proteum diffractometer
Absorption correction	Multi-scan (SADABS in APEX2; Bruker, 2006)
T_min, T_max	0.843, 0.929
No. of measured, independent and observed [I > 2σ(I)] reflections	20812, 2979, 2679
R_int	0.053
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.097, 1.07
No. of reflections	2979
No. of parameters	233
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.20

Computer programs: APEX2 (Bruker, 2006), SHELXS97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and local procedures.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.851 (18)	2.075 (18)	2.8635 (15)	153.8 (16)
N1—H1N···O3ⁱ	0.851 (18)	2.301 (17)	2.9476 (15)	133.0 (15)

Symmetry code: (i) −x+1, y+1/2, −z+3/2.

Acknowledgements

This investigation was supported by NIH/National Cancer Institute grant RO1 CA140409.

References

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