organic compounds
2-(4-Fluorophenyl)-3-methyl-1H-indole
aSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland
*Correspondence e-mail: amzs@st-andrews.ac.uk
The indole N—H hydrogen in the title compound, C15H12FN, does not display classical hydrogen bonding. Rather it forms an interaction with the π system of an adjacent indole, resulting in weakly interacting chains along the [001] direction.
Related literature
The title compound has previously been prepared by Buu-Hoi & Jacquignon (1949) and by Kraus & Guo (2009). For the synthesis of the starting material, 4-fluoro-N-(2-oxo-2-phenylethyl)benzamide, see: Moriya et al. (1986). There are no structures of closely related compounds in the literature. For some similar compounds, see: Schmelter et al. (1973); Konno et al. (2004); Kumar & Liu (2006).
Experimental
Crystal data
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Refinement
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Data collection: CrystalClear (Rigaku, 2010); cell CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536811021325/si2359sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811021325/si2359Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536811021325/si2359Isup3.cml
A suspension of 4-fluoro-N-(2-oxo-2-phenylethyl)benzamide (0.26 g, 1.0 mmol, Moriya et al.1986) and Woollins' reagent (0.54 g, 1.0 mmol) in 20 ml of dry toluene was refluxed for 7 h. Following cooling to room temperature and removal of solvent in vacuuo the residue was purified by silica gel δ), 8.07 (s, 1H, NH), 7.56 (m, 2H, ArH), 7.35 (d, J = 7.7 Hz, 1H, ArH), 7.22–7.09 (m, 5H, ArH), 2.42 (s, 3H, CH3) p.p.m.. 13C NMR (CD2Cl2, δ), 164.0 (C—F), 135.9, 133.1, 129.6, 129.4, 122.3, 119.5, 118.9, 115.9, 115.6, 110.7, 108.5, 9.4 (CH3) p.p.m.. MS (CI+, m/z), 226 [M+H]+. MS (EI+, m/z), 225 [M]+. Accurate mass measurement [EI+, m/z]: 224.0870 [M—H]+, calculated mass for C15H11NF: 224.0870.
(dichloromethane eluent) to give the title compound as a bright grey solid (0.140 g, 62%). Crystals suitable for X-ray were obtained from the diffusion of hexane into a dichloromethane solution of the title compound. M.p. 140 - 141 °C. Selected IR (KBr, cm-1): 3423(s, NH), 1563(m), 1458(m), 1332(m), 1304(m), 1218(s), 1154(m), 838(s), 746(s), 468(m). 1H NMR (CD2Cl2,The NH hydrogen atom was located from the difference fourier map and refined isotropically subject to a distance restraint (N—H = 0.98 Å). Carbon-bound H atoms were included in calculated positions (C—H distances are 0.98 Å for methyl H atoms and 0.95 Å for phenyl H atoms) and refined as riding atoms with Uiso(H) = 1.2 Ueq(parent atom, phenyl H atoms) or Uiso(H) = 1.5 Ueq (parent atom, methyl H atoms).
Data collection: CrystalClear (Rigaku, 2010); cell
CrystalClear (Rigaku, 2010); data reduction: CrystalClear (Rigaku, 2010); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. |
C15H12FN | F(000) = 472 |
Mr = 225.26 | Dx = 1.357 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3217 reflections |
a = 7.790 (3) Å | θ = 2.4–28.3° |
b = 17.125 (6) Å | µ = 0.09 mm−1 |
c = 8.811 (4) Å | T = 93 K |
β = 110.274 (9)° | Platelet, colorless |
V = 1102.7 (8) Å3 | 0.25 × 0.20 × 0.15 mm |
Z = 4 |
Rigaku Mercury CCD diffractometer | 2361 independent reflections |
Radiation source: rotating anode | 1703 reflections with I > 2σ(I) |
Confocal monochromator | Rint = 0.049 |
Detector resolution: 14.7059 pixels mm-1 | θmax = 28.7°, θmin = 2.4° |
ω and ϕ scans | h = −9→9 |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2010) | k = −16→23 |
Tmin = 0.706, Tmax = 1.000 | l = −11→10 |
7380 measured reflections |
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)] = 0.065 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.195 | w = 1/[σ2(Fo2) + (0.1147P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2361 reflections | Δρmax = 0.31 e Å−3 |
160 parameters | Δρmin = −0.21 e Å−3 |
1 restraint | Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.052 (13) |
C15H12FN | V = 1102.7 (8) Å3 |
Mr = 225.26 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.790 (3) Å | µ = 0.09 mm−1 |
b = 17.125 (6) Å | T = 93 K |
c = 8.811 (4) Å | 0.25 × 0.20 × 0.15 mm |
β = 110.274 (9)° |
Rigaku Mercury CCD diffractometer | 2361 independent reflections |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2010) | 1703 reflections with I > 2σ(I) |
Tmin = 0.706, Tmax = 1.000 | Rint = 0.049 |
7380 measured reflections |
R[F2 > 2σ(F2)] = 0.065 | 1 restraint |
wR(F2) = 0.195 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.31 e Å−3 |
2361 reflections | Δρmin = −0.21 e Å−3 |
160 parameters |
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. A distance restraint was applied to the N—H bond. |
x | y | z | Uiso*/Ueq | ||
F1 | 0.44463 (18) | 0.36586 (7) | 0.14270 (16) | 0.0629 (5) | |
N1 | −0.1358 (2) | 0.33607 (9) | 0.5104 (2) | 0.0416 (5) | |
H1 | −0.190 (3) | 0.3064 (13) | 0.416 (2) | 0.070 (7)* | |
C1 | 0.0281 (2) | 0.37720 (10) | 0.5467 (2) | 0.0373 (5) | |
C2 | 0.0708 (2) | 0.41011 (10) | 0.6983 (2) | 0.0392 (5) | |
C3 | −0.0707 (2) | 0.38743 (10) | 0.7584 (2) | 0.0386 (5) | |
C4 | −0.1007 (3) | 0.40028 (10) | 0.9045 (2) | 0.0427 (5) | |
H4 | −0.0164 | 0.4305 | 0.9878 | 0.051* | |
C5 | −0.2529 (3) | 0.36883 (11) | 0.9262 (2) | 0.0456 (5) | |
H5 | −0.2725 | 0.3767 | 1.0256 | 0.055* | |
C6 | −0.3796 (3) | 0.32527 (11) | 0.8028 (2) | 0.0470 (5) | |
H6 | −0.4854 | 0.3053 | 0.8195 | 0.056* | |
C7 | −0.3545 (2) | 0.31077 (11) | 0.6581 (2) | 0.0445 (5) | |
H7 | −0.4404 | 0.2809 | 0.5754 | 0.053* | |
C8 | −0.1987 (2) | 0.34150 (10) | 0.6377 (2) | 0.0392 (5) | |
C9 | 0.2314 (3) | 0.46041 (11) | 0.7870 (2) | 0.0466 (5) | |
H9A | 0.3395 | 0.4421 | 0.7648 | 0.070* | |
H9B | 0.2545 | 0.4574 | 0.9034 | 0.070* | |
H9C | 0.2052 | 0.5146 | 0.7507 | 0.070* | |
C10 | 0.1309 (2) | 0.37612 (10) | 0.4355 (2) | 0.0379 (5) | |
C11 | 0.1282 (2) | 0.30989 (11) | 0.3413 (2) | 0.0420 (5) | |
H11 | 0.0543 | 0.2665 | 0.3462 | 0.050* | |
C12 | 0.2309 (2) | 0.30642 (11) | 0.2413 (2) | 0.0456 (5) | |
H12 | 0.2274 | 0.2616 | 0.1766 | 0.055* | |
C13 | 0.3388 (3) | 0.36986 (12) | 0.2380 (2) | 0.0459 (5) | |
C14 | 0.3432 (3) | 0.43669 (11) | 0.3255 (2) | 0.0446 (5) | |
H14 | 0.4166 | 0.4799 | 0.3188 | 0.054* | |
C15 | 0.2382 (2) | 0.43944 (10) | 0.4235 (2) | 0.0415 (5) | |
H15 | 0.2390 | 0.4854 | 0.4840 | 0.050* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.0641 (9) | 0.0696 (9) | 0.0655 (9) | 0.0056 (7) | 0.0357 (7) | 0.0017 (7) |
N1 | 0.0344 (9) | 0.0434 (9) | 0.0440 (10) | −0.0072 (6) | 0.0099 (7) | −0.0019 (8) |
C1 | 0.0319 (9) | 0.0299 (8) | 0.0474 (11) | −0.0007 (7) | 0.0101 (8) | 0.0018 (8) |
C2 | 0.0325 (9) | 0.0340 (10) | 0.0482 (11) | 0.0003 (7) | 0.0104 (8) | 0.0014 (8) |
C3 | 0.0349 (9) | 0.0319 (9) | 0.0461 (11) | 0.0048 (7) | 0.0104 (8) | 0.0052 (8) |
C4 | 0.0434 (11) | 0.0340 (10) | 0.0484 (12) | 0.0027 (8) | 0.0128 (9) | 0.0020 (9) |
C5 | 0.0476 (12) | 0.0420 (11) | 0.0487 (12) | 0.0023 (8) | 0.0183 (10) | 0.0052 (9) |
C6 | 0.0396 (11) | 0.0448 (11) | 0.0579 (13) | 0.0000 (8) | 0.0187 (9) | 0.0100 (10) |
C7 | 0.0363 (10) | 0.0451 (11) | 0.0479 (12) | −0.0021 (8) | 0.0093 (9) | 0.0062 (9) |
C8 | 0.0322 (9) | 0.0367 (10) | 0.0453 (11) | 0.0011 (7) | 0.0091 (8) | 0.0038 (9) |
C9 | 0.0388 (10) | 0.0448 (11) | 0.0523 (12) | −0.0058 (8) | 0.0107 (9) | −0.0037 (10) |
C10 | 0.0315 (9) | 0.0369 (10) | 0.0412 (11) | 0.0024 (7) | 0.0071 (8) | 0.0024 (8) |
C11 | 0.0378 (10) | 0.0382 (10) | 0.0450 (11) | −0.0014 (7) | 0.0080 (8) | 0.0001 (9) |
C12 | 0.0424 (11) | 0.0450 (12) | 0.0444 (12) | 0.0038 (8) | 0.0085 (9) | −0.0039 (9) |
C13 | 0.0397 (11) | 0.0548 (12) | 0.0440 (11) | 0.0073 (9) | 0.0156 (9) | 0.0043 (10) |
C14 | 0.0371 (10) | 0.0420 (11) | 0.0533 (12) | 0.0007 (8) | 0.0139 (9) | 0.0079 (9) |
C15 | 0.0353 (10) | 0.0356 (10) | 0.0504 (11) | 0.0021 (7) | 0.0106 (8) | 0.0006 (9) |
F1—C13 | 1.367 (2) | C7—C8 | 1.391 (3) |
N1—C8 | 1.374 (2) | C7—H7 | 0.9500 |
N1—C1 | 1.395 (2) | C9—H9A | 0.9800 |
N1—H1 | 0.944 (16) | C9—H9B | 0.9800 |
C1—C2 | 1.380 (3) | C9—H9C | 0.9800 |
C1—C10 | 1.465 (3) | C10—C15 | 1.395 (3) |
C2—C3 | 1.432 (2) | C10—C11 | 1.402 (3) |
C2—C9 | 1.497 (3) | C11—C12 | 1.382 (3) |
C3—C4 | 1.403 (3) | C11—H11 | 0.9500 |
C3—C8 | 1.417 (3) | C12—C13 | 1.380 (3) |
C4—C5 | 1.375 (3) | C12—H12 | 0.9500 |
C4—H4 | 0.9500 | C13—C14 | 1.374 (3) |
C5—C6 | 1.403 (3) | C14—C15 | 1.381 (3) |
C5—H5 | 0.9500 | C14—H14 | 0.9500 |
C6—C7 | 1.378 (3) | C15—H15 | 0.9500 |
C6—H6 | 0.9500 | ||
C8—N1—C1 | 109.61 (16) | C7—C8—C3 | 122.10 (18) |
C8—N1—H1 | 125.6 (14) | C2—C9—H9A | 109.5 |
C1—N1—H1 | 124.7 (14) | C2—C9—H9B | 109.5 |
C2—C1—N1 | 108.81 (16) | H9A—C9—H9B | 109.5 |
C2—C1—C10 | 130.42 (16) | C2—C9—H9C | 109.5 |
N1—C1—C10 | 120.63 (17) | H9A—C9—H9C | 109.5 |
C1—C2—C3 | 106.81 (16) | H9B—C9—H9C | 109.5 |
C1—C2—C9 | 128.14 (17) | C15—C10—C11 | 118.04 (17) |
C3—C2—C9 | 125.05 (17) | C15—C10—C1 | 121.45 (16) |
C4—C3—C8 | 118.57 (17) | C11—C10—C1 | 120.48 (16) |
C4—C3—C2 | 133.71 (18) | C12—C11—C10 | 121.30 (17) |
C8—C3—C2 | 107.71 (17) | C12—C11—H11 | 119.3 |
C5—C4—C3 | 119.44 (18) | C10—C11—H11 | 119.3 |
C5—C4—H4 | 120.3 | C13—C12—C11 | 118.10 (18) |
C3—C4—H4 | 120.3 | C13—C12—H12 | 120.9 |
C4—C5—C6 | 120.67 (18) | C11—C12—H12 | 120.9 |
C4—C5—H5 | 119.7 | F1—C13—C14 | 118.92 (17) |
C6—C5—H5 | 119.7 | F1—C13—C12 | 118.33 (17) |
C7—C6—C5 | 121.69 (18) | C14—C13—C12 | 122.75 (19) |
C7—C6—H6 | 119.2 | C13—C14—C15 | 118.33 (18) |
C5—C6—H6 | 119.2 | C13—C14—H14 | 120.8 |
C6—C7—C8 | 117.49 (18) | C15—C14—H14 | 120.8 |
C6—C7—H7 | 121.3 | C14—C15—C10 | 121.43 (18) |
C8—C7—H7 | 121.3 | C14—C15—H15 | 119.3 |
N1—C8—C7 | 130.84 (17) | C10—C15—H15 | 119.3 |
N1—C8—C3 | 107.05 (16) | ||
C8—N1—C1—C2 | −0.5 (2) | C4—C3—C8—N1 | −178.33 (15) |
C8—N1—C1—C10 | 175.64 (15) | C2—C3—C8—N1 | 0.56 (19) |
N1—C1—C2—C3 | 0.9 (2) | C4—C3—C8—C7 | 1.7 (3) |
C10—C1—C2—C3 | −174.81 (17) | C2—C3—C8—C7 | −179.37 (16) |
N1—C1—C2—C9 | −178.84 (17) | C2—C1—C10—C15 | −35.0 (3) |
C10—C1—C2—C9 | 5.5 (3) | N1—C1—C10—C15 | 149.74 (17) |
C1—C2—C3—C4 | 177.78 (19) | C2—C1—C10—C11 | 143.0 (2) |
C9—C2—C3—C4 | −2.5 (3) | N1—C1—C10—C11 | −32.2 (2) |
C1—C2—C3—C8 | −0.9 (2) | C15—C10—C11—C12 | 1.1 (3) |
C9—C2—C3—C8 | 178.83 (16) | C1—C10—C11—C12 | −176.98 (16) |
C8—C3—C4—C5 | −0.6 (3) | C10—C11—C12—C13 | 0.8 (3) |
C2—C3—C4—C5 | −179.09 (18) | C11—C12—C13—F1 | 178.20 (17) |
C3—C4—C5—C6 | −1.1 (3) | C11—C12—C13—C14 | −2.2 (3) |
C4—C5—C6—C7 | 1.6 (3) | F1—C13—C14—C15 | −178.86 (16) |
C5—C6—C7—C8 | −0.5 (3) | C12—C13—C14—C15 | 1.5 (3) |
C1—N1—C8—C7 | 179.89 (19) | C13—C14—C15—C10 | 0.5 (3) |
C1—N1—C8—C3 | 0.0 (2) | C11—C10—C15—C14 | −1.8 (3) |
C6—C7—C8—N1 | 178.87 (18) | C1—C10—C15—C14 | 176.27 (17) |
C6—C7—C8—C3 | −1.2 (3) |
Cg is the centroid of the C3–C8 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cgi | 0.94 (2) | 2.99 (2) | 3.791 (2) | 143 (2) |
Symmetry code: (i) x, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C15H12FN |
Mr | 225.26 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 93 |
a, b, c (Å) | 7.790 (3), 17.125 (6), 8.811 (4) |
β (°) | 110.274 (9) |
V (Å3) | 1102.7 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.25 × 0.20 × 0.15 |
Data collection | |
Diffractometer | Rigaku Mercury CCD diffractometer |
Absorption correction | Multi-scan (CrystalClear; Rigaku, 2010) |
Tmin, Tmax | 0.706, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7380, 2361, 1703 |
Rint | 0.049 |
(sin θ/λ)max (Å−1) | 0.675 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.065, 0.195, 1.07 |
No. of reflections | 2361 |
No. of parameters | 160 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.31, −0.21 |
Computer programs: CrystalClear (Rigaku, 2010), SHELXTL (Sheldrick, 2008).
Cg is the centroid of the C3–C8 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cgi | 0.944 (16) | 2.99 (2) | 3.791 (2) | 143.4 (16) |
Symmetry code: (i) x, −y+1/2, z−1/2. |
Acknowledgements
The authors are grateful to the University of St Andrews and the Engineering and Physical Science Research Council (EPSRC, UK) for financial support.
References
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The previously known title compound (Buu-Hoi & Jacquignon, 1949 and Kraus & Guo, 2009) has been synthesized by a new route from Woollins' reagent and 4-fluoro-N-(2-oxo-2-phenylethyl)benzamide. The structure of the compound is not closely related to any known structures; however, among those structures showing similarities (Schmelter et al., 1973, Konno et al., 2004, and Kumar & Liu, 2006) the indole N—H shows a tendency toward interactions with π systems, rather than conventional hydrogen bonding, similar to that observed in the title compound.