organic compounds
3-(1H-Indol-3-yl)-2-benzofuran-1(3H)-one
aDepartment of Chemistry, Kuvempu University, PG Centre, Kadur 577 548, India, bInstitution of Excellence, University of Mysore, Manasagangotri, Mysuru 570 006, India, cDepartment of PG Studies in Chemistry, Government Science College, Hassan 573 201, India, dDepartment of Chemistry, Yuvarajas College, University of Mysore, Mysuru 570 005, India, eDepartment of Studies in Physics, University of Mysore, Manasagangotri, Mysuru 570 006, India, and fDepartment of Chemistry, Science College, An-Najah National University, PO Box 7, Nablus, West Bank, Palestinian Territories
*Correspondence e-mail: lokanath@physics.uni-mysore.ac.in, khalil.i@najah.edu
In the title compound, C16H11NO2, the benzofuran and indole ring systems are nearly orthogonal, subtending a dihedral angle of 86.55 (4)°. The features an N—H⋯O hydrogen bond, which leads to the formation of chains propagating along the a-axis direction.
Keywords: crystal structure; indoles; hydrogen bonding.
CCDC reference: 1528890
Structure description
The indole subunit is widely observed in a plethora of natural and synthetic compounds characterized by a variety of biological and pharmacological activities (Mahboobi et al., 2006). Indole derivatives form the basis of a range of pharmaceuticals and a high level of activity continues in the search for new indole-based medicinal agents (Anil Kumar et al., 2016a). In view of the broad spectrum of applications associated with indoles and as a part of our ongoing work on such molecules (Anil Kumar et al., 2016b), we report herein the synthesis and of the title compound.
The structure of the molecule is shown in Fig. 1. The dihedral angle value of 86.55 (4)° between the planes of the benzofuran and indole ring systems indicates that they are nearly orthogonal to one another. In the crystal, molecules are linked via N—H⋯O hydrogen bonds, forming chains propagating along the a-axis direction (Table 1, Fig. 2).
Synthesis and crystallization
The synthesis of the title compound was accomplished by condensation reaction between commercially available indole and 2-formylbenzoic acid in glacial acetic acid at room temperature for 4–6 h. The resultant crude product was purified by recrystallization by using methanol as solvent to get colorless crystals. Yield: 83%, m.p. 174–176 °C.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1528890
https://doi.org/10.1107/S2414314617001079/xu4022sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617001079/xu4022Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314617001079/xu4022Isup3.cml
Data collection: APEX2 (Bruker, 2013); cell
SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: Mercury (Macrae et al., 2008).C16H11NO2 | F(000) = 1040 |
Mr = 249.26 | Dx = 1.356 Mg m−3 |
Orthorhombic, Pbca | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 1970 reflections |
a = 16.522 (3) Å | θ = 5.3–64.3° |
b = 7.6439 (14) Å | µ = 0.73 mm−1 |
c = 19.331 (4) Å | T = 296 K |
V = 2441.4 (8) Å3 | Rectangle, white |
Z = 8 | 0.30 × 0.28 × 0.25 mm |
Bruker X8 Proteum diffractometer | 1999 independent reflections |
Radiation source: Bruker MicroStar microfocus rotating anode | 1970 reflections with I > 2σ(I) |
Helios multilayer optics monochromator | Rint = 0.036 |
Detector resolution: 18.4 pixels mm-1 | θmax = 64.3°, θmin = 5.3° |
φ and ω scans | h = −18→18 |
Absorption correction: multi-scan (SADABS; Bruker, 2013) | k = −8→7 |
Tmin = 0.811, Tmax = 0.839 | l = −22→22 |
11928 measured reflections |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.086 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0342P)2 + 1.1739P] where P = (Fo2 + 2Fc2)/3 |
1999 reflections | (Δ/σ)max < 0.001 |
172 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles |
Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > 2sigma(F2) is used only for calculating -R-factor-obs 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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.43433 (5) | 0.84507 (12) | 0.28595 (4) | 0.0232 (3) | |
O2 | 0.31751 (6) | 0.89685 (13) | 0.34137 (5) | 0.0285 (3) | |
N1 | 0.70014 (7) | 0.92519 (16) | 0.26536 (6) | 0.0284 (4) | |
C1 | 0.68634 (8) | 0.97689 (17) | 0.33228 (7) | 0.0237 (4) | |
C2 | 0.73445 (8) | 1.07594 (18) | 0.37663 (8) | 0.0310 (4) | |
C3 | 0.70652 (9) | 1.10207 (19) | 0.44267 (8) | 0.0335 (4) | |
C4 | 0.63269 (8) | 1.03069 (19) | 0.46506 (8) | 0.0297 (4) | |
C5 | 0.58456 (8) | 0.93417 (17) | 0.42091 (7) | 0.0223 (4) | |
C6 | 0.61104 (8) | 0.90567 (16) | 0.35301 (7) | 0.0194 (3) | |
C7 | 0.58029 (8) | 0.80951 (17) | 0.29459 (6) | 0.0204 (3) | |
C8 | 0.63688 (8) | 0.82481 (18) | 0.24342 (7) | 0.0253 (4) | |
C9 | 0.50181 (7) | 0.71623 (17) | 0.28822 (6) | 0.0209 (4) | |
C10 | 0.47770 (8) | 0.59775 (17) | 0.34676 (6) | 0.0192 (4) | |
C11 | 0.51687 (8) | 0.45282 (17) | 0.37444 (7) | 0.0227 (4) | |
C12 | 0.47774 (9) | 0.36276 (19) | 0.42680 (7) | 0.0275 (4) | |
C13 | 0.40181 (9) | 0.41450 (19) | 0.45134 (7) | 0.0295 (4) | |
C14 | 0.36326 (8) | 0.55958 (18) | 0.42418 (7) | 0.0251 (4) | |
C15 | 0.40316 (8) | 0.65007 (17) | 0.37214 (6) | 0.0201 (4) | |
C16 | 0.37754 (8) | 0.80699 (17) | 0.33410 (6) | 0.0213 (4) | |
H1 | 0.74200 | 0.95180 | 0.24110 | 0.0340* | |
H2 | 0.78360 | 1.12250 | 0.36210 | 0.0370* | |
H3 | 0.73720 | 1.16850 | 0.47330 | 0.0400* | |
H4 | 0.61590 | 1.04880 | 0.51040 | 0.0360* | |
H5 | 0.53540 | 0.88880 | 0.43600 | 0.0270* | |
H8 | 0.63280 | 0.77400 | 0.19980 | 0.0300* | |
H9 | 0.50180 | 0.64880 | 0.24510 | 0.0250* | |
H11 | 0.56740 | 0.41770 | 0.35840 | 0.0270* | |
H12 | 0.50260 | 0.26520 | 0.44620 | 0.0330* | |
H13 | 0.37700 | 0.35060 | 0.48630 | 0.0350* | |
H14 | 0.31270 | 0.59500 | 0.44010 | 0.0300* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0225 (5) | 0.0239 (5) | 0.0233 (5) | 0.0029 (4) | −0.0018 (4) | 0.0050 (4) |
O2 | 0.0240 (5) | 0.0306 (6) | 0.0310 (5) | 0.0070 (4) | −0.0031 (4) | 0.0005 (4) |
N1 | 0.0230 (6) | 0.0315 (7) | 0.0307 (6) | 0.0013 (5) | 0.0091 (5) | 0.0100 (5) |
C1 | 0.0221 (7) | 0.0171 (6) | 0.0320 (7) | 0.0032 (5) | 0.0024 (5) | 0.0068 (6) |
C2 | 0.0209 (7) | 0.0194 (7) | 0.0527 (9) | −0.0016 (6) | −0.0012 (6) | 0.0034 (6) |
C3 | 0.0274 (7) | 0.0232 (7) | 0.0498 (9) | 0.0008 (6) | −0.0110 (7) | −0.0100 (7) |
C4 | 0.0304 (7) | 0.0278 (8) | 0.0309 (7) | 0.0055 (6) | −0.0038 (6) | −0.0082 (6) |
C5 | 0.0213 (6) | 0.0205 (7) | 0.0251 (7) | 0.0014 (5) | 0.0005 (5) | −0.0005 (5) |
C6 | 0.0195 (6) | 0.0148 (6) | 0.0238 (6) | 0.0025 (5) | −0.0002 (5) | 0.0040 (5) |
C7 | 0.0230 (6) | 0.0193 (6) | 0.0188 (6) | 0.0031 (5) | 0.0011 (5) | 0.0039 (5) |
C8 | 0.0274 (7) | 0.0271 (7) | 0.0215 (6) | 0.0062 (6) | 0.0028 (5) | 0.0055 (6) |
C9 | 0.0232 (7) | 0.0208 (7) | 0.0187 (6) | 0.0038 (5) | −0.0013 (5) | −0.0005 (5) |
C10 | 0.0222 (6) | 0.0186 (7) | 0.0168 (6) | −0.0026 (5) | −0.0027 (5) | −0.0035 (5) |
C11 | 0.0231 (7) | 0.0220 (7) | 0.0230 (7) | 0.0025 (5) | −0.0018 (5) | −0.0017 (5) |
C12 | 0.0327 (7) | 0.0232 (7) | 0.0265 (7) | 0.0035 (6) | −0.0027 (6) | 0.0047 (6) |
C13 | 0.0335 (8) | 0.0301 (8) | 0.0248 (7) | −0.0030 (6) | 0.0030 (6) | 0.0065 (6) |
C14 | 0.0239 (7) | 0.0276 (7) | 0.0239 (7) | −0.0008 (6) | 0.0019 (5) | −0.0015 (6) |
C15 | 0.0222 (6) | 0.0195 (7) | 0.0185 (6) | −0.0010 (5) | −0.0041 (5) | −0.0034 (5) |
C16 | 0.0210 (6) | 0.0232 (7) | 0.0196 (6) | −0.0015 (6) | −0.0037 (5) | −0.0029 (5) |
O1—C9 | 1.4882 (15) | C10—C11 | 1.3901 (19) |
O1—C16 | 1.3533 (15) | C11—C12 | 1.384 (2) |
O2—C16 | 1.2146 (17) | C12—C13 | 1.398 (2) |
N1—C1 | 1.3717 (18) | C13—C14 | 1.382 (2) |
N1—C8 | 1.3642 (18) | C14—C15 | 1.3875 (19) |
N1—H1 | 0.8600 | C15—C16 | 1.4692 (18) |
C1—C2 | 1.393 (2) | C2—H2 | 0.9300 |
C1—C6 | 1.4159 (19) | C3—H3 | 0.9300 |
C2—C3 | 1.372 (2) | C4—H4 | 0.9300 |
C3—C4 | 1.405 (2) | C5—H5 | 0.9300 |
C4—C5 | 1.380 (2) | C8—H8 | 0.9300 |
C5—C6 | 1.4006 (19) | C9—H9 | 0.9800 |
C6—C7 | 1.4401 (18) | C11—H11 | 0.9300 |
C7—C9 | 1.4849 (18) | C12—H12 | 0.9300 |
C7—C8 | 1.3661 (18) | C13—H13 | 0.9300 |
C9—C10 | 1.5032 (18) | C14—H14 | 0.9300 |
C10—C15 | 1.3847 (19) | ||
C9—O1—C16 | 110.90 (9) | C10—C15—C16 | 108.34 (11) |
C1—N1—C8 | 109.14 (11) | C14—C15—C16 | 129.27 (12) |
C8—N1—H1 | 125.00 | C10—C15—C14 | 122.38 (12) |
C1—N1—H1 | 125.00 | O2—C16—C15 | 129.72 (12) |
C2—C1—C6 | 122.43 (13) | O1—C16—O2 | 121.61 (11) |
N1—C1—C2 | 129.96 (13) | O1—C16—C15 | 108.67 (11) |
N1—C1—C6 | 107.59 (11) | C1—C2—H2 | 121.00 |
C1—C2—C3 | 117.38 (13) | C3—C2—H2 | 121.00 |
C2—C3—C4 | 121.48 (14) | C2—C3—H3 | 119.00 |
C3—C4—C5 | 121.16 (14) | C4—C3—H3 | 119.00 |
C4—C5—C6 | 118.86 (12) | C3—C4—H4 | 119.00 |
C1—C6—C5 | 118.68 (12) | C5—C4—H4 | 119.00 |
C5—C6—C7 | 134.76 (12) | C4—C5—H5 | 121.00 |
C1—C6—C7 | 106.52 (11) | C6—C5—H5 | 121.00 |
C6—C7—C9 | 128.19 (11) | N1—C8—H8 | 125.00 |
C6—C7—C8 | 106.42 (12) | C7—C8—H8 | 125.00 |
C8—C7—C9 | 125.36 (11) | O1—C9—H9 | 109.00 |
N1—C8—C7 | 110.33 (12) | C7—C9—H9 | 109.00 |
O1—C9—C7 | 109.81 (10) | C10—C9—H9 | 109.00 |
C7—C9—C10 | 117.28 (10) | C10—C11—H11 | 121.00 |
O1—C9—C10 | 102.85 (9) | C12—C11—H11 | 121.00 |
C9—C10—C15 | 109.17 (11) | C11—C12—H12 | 119.00 |
C11—C10—C15 | 120.52 (12) | C13—C12—H12 | 119.00 |
C9—C10—C11 | 130.28 (12) | C12—C13—H13 | 120.00 |
C10—C11—C12 | 117.41 (12) | C14—C13—H13 | 120.00 |
C11—C12—C13 | 121.76 (13) | C13—C14—H14 | 121.00 |
C12—C13—C14 | 120.76 (13) | C15—C14—H14 | 121.00 |
C13—C14—C15 | 117.15 (12) | ||
C16—O1—C9—C7 | −127.15 (10) | C6—C7—C9—O1 | 69.43 (16) |
C16—O1—C9—C10 | −1.57 (12) | C6—C7—C9—C10 | −47.42 (19) |
C9—O1—C16—O2 | 179.41 (11) | C8—C7—C9—O1 | −108.12 (14) |
C9—O1—C16—C15 | 0.14 (13) | C8—C7—C9—C10 | 135.03 (13) |
C8—N1—C1—C2 | 178.09 (14) | O1—C9—C10—C11 | −179.29 (13) |
C8—N1—C1—C6 | −0.05 (14) | O1—C9—C10—C15 | 2.50 (13) |
C1—N1—C8—C7 | 0.51 (16) | C7—C9—C10—C11 | −58.72 (18) |
N1—C1—C2—C3 | −177.39 (14) | C7—C9—C10—C15 | 123.07 (12) |
C6—C1—C2—C3 | 0.5 (2) | C9—C10—C11—C12 | −176.83 (13) |
N1—C1—C6—C5 | 177.48 (12) | C15—C10—C11—C12 | 1.21 (19) |
N1—C1—C6—C7 | −0.40 (14) | C9—C10—C15—C14 | 176.57 (12) |
C2—C1—C6—C5 | −0.8 (2) | C9—C10—C15—C16 | −2.51 (14) |
C2—C1—C6—C7 | −178.71 (12) | C11—C10—C15—C14 | −1.9 (2) |
C1—C2—C3—C4 | 0.5 (2) | C11—C10—C15—C16 | 179.07 (12) |
C2—C3—C4—C5 | −1.3 (2) | C10—C11—C12—C13 | −0.1 (2) |
C3—C4—C5—C6 | 0.9 (2) | C11—C12—C13—C14 | −0.5 (2) |
C4—C5—C6—C1 | 0.09 (19) | C12—C13—C14—C15 | −0.1 (2) |
C4—C5—C6—C7 | 177.22 (14) | C13—C14—C15—C10 | 1.2 (2) |
C1—C6—C7—C8 | 0.70 (14) | C13—C14—C15—C16 | −179.89 (13) |
C1—C6—C7—C9 | −177.22 (12) | C10—C15—C16—O1 | 1.51 (14) |
C5—C6—C7—C8 | −176.68 (15) | C10—C15—C16—O2 | −177.68 (13) |
C5—C6—C7—C9 | 5.4 (2) | C14—C15—C16—O1 | −177.49 (13) |
C6—C7—C8—N1 | −0.75 (15) | C14—C15—C16—O2 | 3.3 (2) |
C9—C7—C8—N1 | 177.24 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O2i | 0.86 | 2.07 | 2.8398 (16) | 149 |
Symmetry code: (i) x+1/2, y, −z+1/2. |
Acknowledgements
The authors are grateful to the Institution of Excellence, Vijnana Bhavana, University of Mysore, India, for providing the single-crystal X-ray diffractometer facility. RAK thanks UGC for financial assistance from BSR fellowship.
References
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