In the title compound, C
19H
18N
2O
4, the indole moiety is planar and the dihedral angle between it and the substituted phenyl ring is 24.38 (5)°. In the solid state, inversion-related molecules are linked to form N—H
O hydrogen-bonded dimers. The molecular packing is stabilized by C—H
π interactions.
Supporting information
CCDC reference: 214622
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.061
- wR factor = 0.189
- Data-to-parameter ratio = 18.0
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
1-(Indol-2-yl)-2-(6-nitrovertatryl)ethene (0.68 g, 2 mmol) and sodium ethoxide (0.24 g, 5 mmol) were taken in dry THF (40 ml) and refluxed for 6 h. The solution was cooled and poured over crushed ice. The preciptated solid was filtered, washed with water (2 × 5 ml) and dried over CaCl2. This was recrystallized from ethanol to afford the title compound.
The H atoms were geometrically positioned and were treated as riding on the parent atoms, with C—H distances in the range 0.93–0.97 Å and N—H distance of 0.86 Å. The rotating group refinement was used for the methyl groups.
Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1997) and PLATON (Spek, 1990); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).
2-[2-(4-Ethoxy-5-methoxy-2-nitrophenyl)vinyl]-1
H-indole
top
Crystal data top
C19H18N2O4 | Z = 2 |
Mr = 338.35 | F(000) = 356 |
Triclinic, P1 | Dx = 1.306 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.5949 (4) Å | Cell parameters from 3349 reflections |
b = 10.0887 (6) Å | θ = 1.8–28.3° |
c = 11.5777 (7) Å | µ = 0.09 mm−1 |
α = 85.298 (1)° | T = 293 K |
β = 76.924 (1)° | Plate, red |
γ = 86.166 (1)° | 0.44 × 0.28 × 0.16 mm |
V = 860.14 (9) Å3 | |
Data collection top
Siemens SMART CCD area-detector diffractometer | 2759 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Graphite monochromator | θmax = 28.3°, θmin = 1.8° |
ω scans | h = −8→10 |
5992 measured reflections | k = −13→13 |
4109 independent reflections | l = −15→12 |
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)] = 0.061 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.189 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.1036P)2 + 0.0867P] where P = (Fo2 + 2Fc2)/3 |
4109 reflections | (Δ/σ)max < 0.001 |
228 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
Crystal data top
C19H18N2O4 | γ = 86.166 (1)° |
Mr = 338.35 | V = 860.14 (9) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.5949 (4) Å | Mo Kα radiation |
b = 10.0887 (6) Å | µ = 0.09 mm−1 |
c = 11.5777 (7) Å | T = 293 K |
α = 85.298 (1)° | 0.44 × 0.28 × 0.16 mm |
β = 76.924 (1)° | |
Data collection top
Siemens SMART CCD area-detector diffractometer | 2759 reflections with I > 2σ(I) |
5992 measured reflections | Rint = 0.025 |
4109 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.061 | 0 restraints |
wR(F2) = 0.189 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.23 e Å−3 |
4109 reflections | Δρmin = −0.23 e Å−3 |
228 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 | Uiso*/Ueq | |
O1 | 0.38514 (19) | 0.31020 (13) | −0.06658 (11) | 0.0539 (4) | |
O2 | 0.4804 (2) | 0.13263 (13) | 0.08272 (12) | 0.0586 (4) | |
O3 | 0.2156 (3) | 0.51133 (18) | 0.45182 (14) | 0.0933 (6) | |
O4 | 0.2176 (3) | 0.30062 (18) | 0.47735 (13) | 0.0910 (6) | |
N1 | −0.0386 (3) | 0.87630 (16) | 0.32494 (15) | 0.0588 (5) | |
H1 | −0.0590 | 0.8144 | 0.3812 | 0.071* | |
C2 | 0.0604 (3) | 0.85939 (19) | 0.21157 (17) | 0.0500 (4) | |
C3 | 0.0622 (3) | 0.9808 (2) | 0.1486 (2) | 0.0598 (5) | |
H3 | 0.1203 | 0.9978 | 0.0694 | 0.072* | |
C4 | −0.0393 (3) | 1.07595 (19) | 0.2241 (2) | 0.0573 (5) | |
C5 | −0.1001 (3) | 1.00694 (19) | 0.3348 (2) | 0.0582 (5) | |
C6 | −0.2040 (4) | 1.0692 (3) | 0.4316 (3) | 0.0858 (8) | |
H6 | −0.2440 | 1.0220 | 0.5042 | 0.103* | |
C7 | −0.2458 (5) | 1.2027 (3) | 0.4164 (3) | 0.0971 (10) | |
H7 | −0.3153 | 1.2466 | 0.4801 | 0.117* | |
C8 | −0.1879 (4) | 1.2733 (3) | 0.3098 (4) | 0.0918 (9) | |
H8 | −0.2180 | 1.3640 | 0.3029 | 0.110* | |
C9 | −0.0867 (3) | 1.2130 (2) | 0.2135 (3) | 0.0784 (8) | |
H9 | −0.0494 | 1.2621 | 0.1415 | 0.094* | |
C10 | 0.1458 (3) | 0.73275 (19) | 0.17516 (17) | 0.0513 (5) | |
H10 | 0.2180 | 0.7306 | 0.0988 | 0.062* | |
C11 | 0.1292 (3) | 0.61877 (18) | 0.24236 (17) | 0.0502 (5) | |
H11 | 0.0539 | 0.6202 | 0.3178 | 0.060* | |
C12 | 0.2206 (2) | 0.49116 (17) | 0.20652 (15) | 0.0449 (4) | |
C13 | 0.2612 (2) | 0.46289 (18) | 0.08610 (15) | 0.0457 (4) | |
H13 | 0.2296 | 0.5267 | 0.0307 | 0.055* | |
C14 | 0.3461 (2) | 0.34426 (18) | 0.04690 (15) | 0.0438 (4) | |
C15 | 0.3962 (2) | 0.24551 (18) | 0.12914 (15) | 0.0447 (4) | |
C16 | 0.3539 (3) | 0.26872 (18) | 0.24771 (15) | 0.0468 (4) | |
H16 | 0.3828 | 0.2041 | 0.3034 | 0.056* | |
C17 | 0.2679 (3) | 0.38900 (18) | 0.28445 (15) | 0.0465 (4) | |
C18 | 0.3282 (3) | 0.4009 (2) | −0.15483 (16) | 0.0531 (5) | |
H18A | 0.3841 | 0.4854 | −0.1596 | 0.064* | |
H18B | 0.1978 | 0.4167 | −0.1351 | 0.064* | |
C19 | 0.3865 (3) | 0.3368 (2) | −0.27094 (18) | 0.0679 (6) | |
H19A | 0.5155 | 0.3209 | −0.2889 | 0.102* | |
H19B | 0.3521 | 0.3948 | −0.3329 | 0.102* | |
H19C | 0.3292 | 0.2538 | −0.2652 | 0.102* | |
C20 | 0.5163 (3) | 0.0253 (2) | 0.1640 (2) | 0.0606 (5) | |
H20A | 0.5972 | 0.0530 | 0.2092 | 0.091* | |
H20B | 0.5709 | −0.0495 | 0.1205 | 0.091* | |
H20C | 0.4050 | 0.0005 | 0.2168 | 0.091* | |
N21 | 0.2303 (3) | 0.40219 (18) | 0.41256 (14) | 0.0589 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0717 (9) | 0.0553 (8) | 0.0345 (6) | 0.0050 (6) | −0.0125 (6) | −0.0055 (6) |
O2 | 0.0791 (10) | 0.0499 (8) | 0.0452 (7) | 0.0086 (7) | −0.0133 (7) | −0.0057 (6) |
O3 | 0.165 (2) | 0.0682 (11) | 0.0490 (9) | 0.0046 (11) | −0.0266 (10) | −0.0191 (8) |
O4 | 0.1530 (19) | 0.0694 (11) | 0.0397 (8) | 0.0003 (11) | −0.0052 (9) | 0.0102 (7) |
N1 | 0.0857 (13) | 0.0405 (9) | 0.0478 (9) | 0.0030 (8) | −0.0132 (8) | 0.0016 (7) |
C2 | 0.0521 (10) | 0.0472 (10) | 0.0514 (10) | −0.0064 (8) | −0.0133 (8) | 0.0009 (8) |
C3 | 0.0539 (12) | 0.0592 (12) | 0.0627 (12) | −0.0106 (9) | −0.0102 (10) | 0.0159 (10) |
C4 | 0.0523 (11) | 0.0448 (10) | 0.0792 (14) | −0.0094 (8) | −0.0262 (10) | 0.0094 (10) |
C5 | 0.0734 (13) | 0.0412 (10) | 0.0648 (13) | 0.0021 (9) | −0.0265 (11) | −0.0047 (9) |
C6 | 0.125 (2) | 0.0616 (15) | 0.0705 (15) | 0.0189 (14) | −0.0228 (15) | −0.0159 (12) |
C7 | 0.122 (3) | 0.0619 (16) | 0.113 (2) | 0.0234 (16) | −0.037 (2) | −0.0308 (17) |
C8 | 0.0894 (19) | 0.0463 (13) | 0.148 (3) | 0.0085 (13) | −0.045 (2) | −0.0123 (17) |
C9 | 0.0685 (15) | 0.0494 (13) | 0.119 (2) | −0.0117 (11) | −0.0319 (15) | 0.0228 (13) |
C10 | 0.0520 (11) | 0.0516 (11) | 0.0482 (10) | −0.0040 (8) | −0.0071 (8) | −0.0019 (8) |
C11 | 0.0559 (11) | 0.0492 (11) | 0.0440 (9) | −0.0024 (8) | −0.0069 (8) | −0.0058 (8) |
C12 | 0.0488 (10) | 0.0453 (9) | 0.0394 (9) | −0.0071 (7) | −0.0062 (7) | −0.0028 (7) |
C13 | 0.0524 (10) | 0.0441 (10) | 0.0396 (9) | −0.0038 (7) | −0.0097 (8) | 0.0015 (7) |
C14 | 0.0476 (10) | 0.0481 (9) | 0.0355 (8) | −0.0064 (7) | −0.0078 (7) | −0.0028 (7) |
C15 | 0.0497 (10) | 0.0426 (9) | 0.0415 (9) | −0.0023 (7) | −0.0094 (8) | −0.0038 (7) |
C16 | 0.0587 (11) | 0.0441 (10) | 0.0374 (9) | −0.0049 (8) | −0.0116 (8) | 0.0026 (7) |
C17 | 0.0560 (11) | 0.0489 (10) | 0.0335 (8) | −0.0083 (8) | −0.0067 (7) | −0.0015 (7) |
C18 | 0.0600 (12) | 0.0604 (12) | 0.0407 (9) | −0.0018 (9) | −0.0157 (8) | −0.0017 (8) |
C19 | 0.0858 (16) | 0.0793 (15) | 0.0419 (10) | −0.0006 (12) | −0.0209 (10) | −0.0076 (10) |
C20 | 0.0749 (14) | 0.0509 (11) | 0.0589 (12) | 0.0060 (10) | −0.0239 (10) | −0.0031 (9) |
N21 | 0.0798 (12) | 0.0587 (10) | 0.0363 (8) | −0.0023 (8) | −0.0093 (8) | −0.0036 (7) |
Geometric parameters (Å, º) top
O1—C14 | 1.348 (2) | C10—C11 | 1.331 (3) |
O1—C18 | 1.436 (2) | C10—H10 | 0.93 |
O2—C15 | 1.357 (2) | C11—C12 | 1.466 (2) |
O2—C20 | 1.429 (2) | C11—H11 | 0.93 |
O3—N21 | 1.214 (2) | C12—C17 | 1.397 (3) |
O4—N21 | 1.215 (2) | C12—C13 | 1.407 (2) |
N1—C5 | 1.374 (2) | C13—C14 | 1.381 (3) |
N1—C2 | 1.375 (3) | C13—H13 | 0.93 |
N1—H1 | 0.86 | C14—C15 | 1.415 (2) |
C2—C3 | 1.372 (3) | C15—C16 | 1.373 (2) |
C2—C10 | 1.444 (3) | C16—C17 | 1.390 (3) |
C3—C4 | 1.420 (3) | C16—H16 | 0.93 |
C3—H3 | 0.93 | C17—N21 | 1.461 (2) |
C4—C5 | 1.403 (3) | C18—C19 | 1.502 (3) |
C4—C9 | 1.408 (3) | C18—H18A | 0.97 |
C5—C6 | 1.387 (3) | C18—H18B | 0.97 |
C6—C7 | 1.369 (4) | C19—H19A | 0.96 |
C6—H6 | 0.93 | C19—H19B | 0.96 |
C7—C8 | 1.369 (4) | C19—H19C | 0.96 |
C7—H7 | 0.93 | C20—H20A | 0.96 |
C8—C9 | 1.365 (4) | C20—H20B | 0.96 |
C8—H8 | 0.93 | C20—H20C | 0.96 |
C9—H9 | 0.93 | | |
| | | |
C14—O1—C18 | 118.32 (14) | C13—C12—C11 | 119.93 (17) |
C15—O2—C20 | 117.57 (15) | C14—C13—C12 | 122.66 (17) |
C5—N1—C2 | 109.78 (17) | C14—C13—H13 | 118.7 |
C5—N1—H1 | 125.1 | C12—C13—H13 | 118.7 |
C2—N1—H1 | 125.1 | O1—C14—C13 | 125.5 (2) |
C3—C2—N1 | 107.60 (17) | O1—C14—C15 | 114.6 (2) |
C3—C2—C10 | 129.88 (19) | C13—C14—C15 | 119.95 (15) |
N1—C2—C10 | 122.49 (17) | O2—C15—C16 | 125.3 (2) |
C2—C3—C4 | 108.72 (19) | O2—C15—C14 | 116.0 (2) |
C2—C3—H3 | 125.6 | C16—C15—C14 | 118.75 (16) |
C4—C3—H3 | 125.6 | C15—C16—C17 | 119.92 (17) |
C5—C4—C9 | 117.7 (2) | C15—C16—H16 | 120.0 |
C5—C4—C3 | 106.05 (17) | C17—C16—H16 | 120.0 |
C9—C4—C3 | 136.2 (2) | C16—C17—C12 | 123.52 (16) |
N1—C5—C6 | 130.0 (2) | C16—C17—N21 | 114.91 (16) |
N1—C5—C4 | 107.84 (18) | C12—C17—N21 | 121.57 (16) |
C6—C5—C4 | 122.2 (2) | O1—C18—C19 | 106.67 (16) |
C7—C6—C5 | 117.7 (3) | O1—C18—H18A | 110.4 |
C7—C6—H6 | 121.2 | C19—C18—H18A | 110.4 |
C5—C6—H6 | 121.2 | O1—C18—H18B | 110.4 |
C6—C7—C8 | 121.7 (3) | C19—C18—H18B | 110.4 |
C6—C7—H7 | 119.2 | H18A—C18—H18B | 108.6 |
C8—C7—H7 | 119.2 | C18—C19—H19A | 109.5 |
C9—C8—C7 | 121.3 (2) | C18—C19—H19B | 109.5 |
C9—C8—H8 | 119.4 | H19A—C19—H19B | 109.5 |
C7—C8—H8 | 119.4 | C18—C19—H19C | 109.5 |
C8—C9—C4 | 119.5 (3) | H19A—C19—H19C | 109.5 |
C8—C9—H9 | 120.3 | H19B—C19—H19C | 109.5 |
C4—C9—H9 | 120.3 | O2—C20—H20A | 109.5 |
C11—C10—C2 | 125.09 (18) | O2—C20—H20B | 109.5 |
C11—C10—H10 | 117.5 | H20A—C20—H20B | 109.5 |
C2—C10—H10 | 117.5 | O2—C20—H20C | 109.5 |
C10—C11—C12 | 124.98 (18) | H20A—C20—H20C | 109.5 |
C10—C11—H11 | 117.5 | H20B—C20—H20C | 109.5 |
C12—C11—H11 | 117.5 | O3—N21—O4 | 121.71 (17) |
C17—C12—C13 | 115.15 (16) | O3—N21—C17 | 120.58 (17) |
C17—C12—C11 | 124.88 (16) | O4—N21—C17 | 117.70 (17) |
| | | |
C5—N1—C2—C3 | 0.1 (2) | C11—C12—C13—C14 | −179.61 (17) |
C5—N1—C2—C10 | 178.67 (17) | C18—O1—C14—C13 | −2.8 (3) |
N1—C2—C3—C4 | −0.4 (2) | C18—O1—C14—C15 | 175.91 (16) |
C10—C2—C3—C4 | −178.82 (19) | C12—C13—C14—O1 | 178.52 (17) |
C2—C3—C4—C5 | 0.5 (2) | C12—C13—C14—C15 | −0.2 (3) |
C2—C3—C4—C9 | 179.8 (2) | C20—O2—C15—C16 | 4.9 (3) |
C2—N1—C5—C6 | −179.9 (2) | C20—O2—C15—C14 | −173.73 (17) |
C2—N1—C5—C4 | 0.2 (2) | O1—C14—C15—O2 | 1.8 (2) |
C9—C4—C5—N1 | −179.91 (18) | C13—C14—C15—O2 | −179.40 (16) |
C3—C4—C5—N1 | −0.5 (2) | O1—C14—C15—C16 | −176.92 (16) |
C9—C4—C5—C6 | 0.2 (3) | C13—C14—C15—C16 | 1.9 (3) |
C3—C4—C5—C6 | 179.7 (2) | O2—C15—C16—C17 | 179.71 (17) |
N1—C5—C6—C7 | 179.8 (3) | C14—C15—C16—C17 | −1.7 (3) |
C4—C5—C6—C7 | −0.4 (4) | C15—C16—C17—C12 | −0.2 (3) |
C5—C6—C7—C8 | 0.0 (5) | C15—C16—C17—N21 | −179.89 (17) |
C6—C7—C8—C9 | 0.5 (5) | C13—C12—C17—C16 | 1.9 (3) |
C7—C8—C9—C4 | −0.7 (4) | C11—C12—C17—C16 | 179.70 (17) |
C5—C4—C9—C8 | 0.3 (3) | C13—C12—C17—N21 | −178.47 (16) |
C3—C4—C9—C8 | −178.9 (2) | C11—C12—C17—N21 | −0.6 (3) |
C3—C2—C10—C11 | −177.0 (2) | C14—O1—C18—C19 | −179.10 (16) |
N1—C2—C10—C11 | 4.7 (3) | C16—C17—N21—O3 | 154.4 (2) |
C2—C10—C11—C12 | −177.99 (17) | C12—C17—N21—O3 | −25.2 (3) |
C10—C11—C12—C17 | 151.7 (2) | C16—C17—N21—O4 | −24.3 (3) |
C10—C11—C12—C13 | −30.5 (3) | C12—C17—N21—O4 | 156.0 (2) |
C17—C12—C13—C14 | −1.7 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11···O3 | 0.93 | 2.35 | 2.771 (3) | 107 |
N1—H1···O4i | 0.86 | 2.11 | 2.919 (2) | 156 |
C18—H18A···CgBii | 0.97 | 2.84 | 3.714 (2) | 150 |
C20—H20A···CgAiii | 0.96 | 2.81 | 3.770 (3) | 175 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) x+1, y−1, z. |
Experimental details
Crystal data |
Chemical formula | C19H18N2O4 |
Mr | 338.35 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 7.5949 (4), 10.0887 (6), 11.5777 (7) |
α, β, γ (°) | 85.298 (1), 76.924 (1), 86.166 (1) |
V (Å3) | 860.14 (9) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.44 × 0.28 × 0.16 |
|
Data collection |
Diffractometer | Siemens SMART CCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5992, 4109, 2759 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.667 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.061, 0.189, 1.02 |
No. of reflections | 4109 |
No. of parameters | 228 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.23 |
Selected geometric parameters (Å, º) topO1—C14 | 1.348 (2) | N1—C5 | 1.374 (2) |
O1—C18 | 1.436 (2) | N1—C2 | 1.375 (3) |
O2—C15 | 1.357 (2) | C2—C10 | 1.444 (3) |
O2—C20 | 1.429 (2) | C10—C11 | 1.331 (3) |
O3—N21 | 1.214 (2) | C11—C12 | 1.466 (2) |
O4—N21 | 1.215 (2) | C17—N21 | 1.461 (2) |
| | | |
O1—C14—C13 | 125.5 (2) | O2—C15—C16 | 125.3 (2) |
O1—C14—C15 | 114.6 (2) | O2—C15—C14 | 116.0 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C11—H11···O3 | 0.93 | 2.35 | 2.771 (3) | 107 |
N1—H1···O4i | 0.86 | 2.11 | 2.919 (2) | 156 |
C18—H18A···CgBii | 0.97 | 2.84 | 3.714 (2) | 150 |
C20—H20A···CgAiii | 0.96 | 2.81 | 3.770 (3) | 175 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) x+1, y−1, z. |
Substituted-indole compounds have gained much importance in the past years, since they are present in a number of natural products, many of which are found to possess antibacterial (Okabe & Adachi, 1998), antitumour (Schollmeyer et al., 1995), antidepressant (Grinev et al., 1984), antimicrobial (El-Sayed et al., 1986; Gadaginamath & Patil, 1999) and anti-inflammatory (Rodriguez et al., 1985) activities. The interaction of a phenylsulfonyl indole with calf-thymus DNA has been reported (Sivaraman et al., 1996). Indoles have been proved to dispaly high aldose reductose inhibitory activity (Rajeswaran et al., 1999). 2-Aroylindole derivatives are found to possess high cytotoxicity and are used as antimitotic agents (Mahboobi et al., 2001). The structure determination of the title compound, (I), was undertaken as part of our studies on indole derivatives.
The bond lengths and angles observed in the indole ring system show normal values. The Csp2—Csp2 single bond distances, C2—C10 [1.444 (3) Å] and C11—C12 [1.466 (2) Å], and Csp2—Csp2 double-bond distance C10═C11 [1.331 (3) Å] are comparable with the corresponding mean value of 1.455 (11) and 1.330 (14) Å, reported by Allen et al. (1987). These bond distances indicate conjugation along C3—C2—C9—C10—C11—C12. The C2—C10 bond is trans to C10—C11 [C2—C10—C11—C12 = −178.0 (2)°]. The dihedral angle between the indole plane and phenyl ring is 24.38 (5)°; the N1—C2—C10—C11 and C10—C11—C12—C13 torsion angles are 4.7 (3) and −30.5 (3)°, respectively.
The NO2 group is twisted away from the attached phenyl ring with C12—C17—N21—O3 and C16—C17—N21—O4 torsion angles being −25.2 (3) and −24.3 (3)°, respectively. The rotation of the NO2 group is restricted by a weak C11—H11···O3 interaction. The N—O distances in the nitro group agree with the mean value of 1.217 (11) Å (Allen et al., 1987). The coplanarity of the methoxy carbon with the phenyl ring [C20—O2—C15—C16 = 4.9 (3)°] results in H16···H20A (2.30 Å) and H16···H20C (2.34 Å) short contacts. These contacts cause the widening of O2—C15—C16 [125.3 (2)°] and narrowing of O2—C15—C14 [116.0 (2)°] angles from 120°. Similar features have been reported in structures containing methoxy substituents (Chandrakantha et al., 1990; Wakahara et al., 1972; Falkenberg & Carlstrom, 1971; Sakaki et al., 1975). The ethoxy group is also coplanar with the phenyl ring with C14—O1—C18—C19 = −179.1 (2) and C18—O1—C14—C13 = −2.8 (3)°; the resultant H13···H18A [2.31 Å] and H13···H18B [2.36 Å] short contacts cause the widening of C13—C14—O1 [125.5 (2)°] and narrowing of C15—C14—O1 [114.6 (2)°] angles, as reported in the literature (Chandrakantha et al., 1998; Sakaki et al., 1976).
One of the nitro group O atoms, O3, is involved in an intramolecular C11—H11···O3 interaction. The other O atom, O4, is involved in the formation of centro-symmetrically N1—H1···O4(-x, 1 − y, 1 − z) hydrogen-bonded dimers, in the solid state. Apart from these interactions, the molecular packing is also stabilized by C—H···π interactions (Table 2 and Fig. 2). In Table 2, CgA and CgB denote the centriods of the rings A and B, respectively.