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Acta Crystallogr Sect E Struct Rep Online. 2009 July 1; 65(Pt 7): o1596.
Published online 2009 June 17. doi:  10.1107/S1600536809022065
PMCID: PMC2969275

2,4-Bis(2-fluoro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

Abstract

The title compound, C20H19F2NO, exists in a twin-chair conformation with an equatorial orientation of the two 2-fluoro­phenyl groups on both sides of the secondary amine group. The benzene rings are orientated at an angle of 25.68 (4)° with respect to one another and the F atoms point upwards (towards the carbonyl group). The crystal is stabilized by an inter­molecular N—H(...)π inter­action.

Related literature

3-Aza­bicyclo­nona­nes are present in numerous naturally occurring diterpenoid/norditerpenoid alkaloids and display broad-spectrum biological activity, see: Hardick et al. (1996 [triangle]); Jeyaraman et al. (1981 [triangle]); For related structures, see: Parthiban et al. (2008a [triangle],b [triangle], 2009 [triangle]); Parthiban, Ramkumar, Kim et al. (2008 [triangle]); Parthiban, Ramkumar, Santan et al. (2008 [triangle]); Parthiban, Thirumurugan et al. (2008 [triangle]). For puckering parameters, see: Cremer & Pople (1975 [triangle]).

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Object name is e-65-o1596-scheme1.jpg

Experimental

Crystal data

  • C20H19F2NO
  • M r = 327.36
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o1596-efi1.jpg
  • a = 7.4699 (3) Å
  • b = 10.6621 (4) Å
  • c = 10.7131 (4) Å
  • α = 78.027 (2)°
  • β = 78.946 (2)°
  • γ = 87.201 (2)°
  • V = 819.16 (5) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.10 mm−1
  • T = 298 K
  • 0.42 × 0.38 × 0.12 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 1999 [triangle]) T min = 0.960, T max = 0.989
  • 11219 measured reflections
  • 3913 independent reflections
  • 2564 reflections with I > 2σ(I)
  • R int = 0.021

Refinement

  • R[F 2 > 2σ(F 2)] = 0.045
  • wR(F 2) = 0.156
  • S = 0.81
  • 3913 reflections
  • 221 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.17 e Å−3
  • Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: SAINT-Plus (Bruker, 2004 [triangle]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]); software used to prepare material for publication: SHELXL97.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809022065/bq2146sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809022065/bq2146Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors acknowledge the Department of Chemistry, IIT Madras, for the X-ray data collection.

supplementary crystallographic information

Comment

3-Azabicyclononanes are important class of heterocycles due to their presence in numerous naturally occurring diterpenoid/norditerpenoid alkaloids and broad spectrum biological activities (Jeyaraman & Avila, 1981; Hardick et al., 1996). Since the stereochemistry plays crucial role in exploiting biological activities, it is essential to establish the stereochemistry of the bio-active molecules. Irrespective of the nature and position of the substituents on the phenyl, similar compounds show twin-chair conformation (Parthiban et al. (2008a,b, 2009; Parthiban, Ramkumar, Kim et al. (2008), Parthiban, Ramkumar, Santanet al., 2008; ; Parthiban, Thirumurugan et al.,2008). However, to explore the impact of fluorine atom, substituted at ortho position of the phenyl groups on both sides of the hetero atom, we have carried out the single-crystal x-ray diffraction study for the title compound.

The title compound C20H19F2NO, (I), exists in twin-chair conformation with equatorial orientation of the ortho-fluorophenyl group on both sides of the secondary amino group with the torsion angle of C8—C2—C1—C9 and C8—C6—C7—C15 as 179.99 (3) and 179.48 (4)°, respectively. The aryl groups are orientated at an angle of 25.68 (4)° to each other. In both aryl groups, the F atom is pointed towards the carbonyl group (Figure 1.). Analysis of torsion angles, asymmetry parameters and least-squares plane calculation shows that the piperidine ring adopts near ideal chair conformation with the deviation of ring atoms N1 and C8 from the C1/C2/C6/C7 plane by -0.654 (3) Å and 0.696 (3) Å, respectively; QT = 0.6002 (18) Å, q(2)= 0.0242 (17) Å, q(3)=-0.5996 (18) Å, θ = 177.54 (16)° whereas the cyclohexane ring atoms C4 and C8 deviate from the C2/C3/C5/C6 plane by -0.529 (4) Å and 0.727 (3) Å, respectively; QT = 0.565 (2) Å, q(2)= 0.146 (2) Å, q(3)= -0.546 (2) Å, θ = 165.1 (2)° (Cremer & Pople, 1975). Hence, the title compound (I) shows appreciable deviation from the ideal chair conformation of the cyclohexane moiety. The crystal structure is stabilized by intermolecular N—H···π interaction (Figure 2.).

Experimental

A mixture of cyclohexanone (0.025 mol, 2.45 g) and ortho-fluorobenzaldehyde (0.05 mol, 6.21 g) was added to a warm solution of ammonium acetate (0.04 mol, 3.08 g) in 30 ml of absolute ethanol. The mixture was gently warmed with stirring till the yellow color was formed during the mixing of the reactants and then stirred at room temperature up to the formation of product. At the end, the crude azabicyclic ketone was separated by filtration and washed with 1:5 ethanol-ether mixture to remove the coloring impurities. Recrystallization of the compound from acetone gave X-ray diffraction quality crystals of 2,4-bis(2-fluorophenyl)-3-azabicyclo[3.3.1]nonan-9-one.

Refinement

Nitrogen H atoms were located in a difference Fourier map and refined isotropically. Other hydrogen atoms were fixed geometrically and allowed to ride on the parent carbon atoms, with aromatic C—H =0.93 Å, aliphatic C—H = 0.98 Å and methylen C—H = 0.97 Å. The displacement parameters were set for phenyl, methylen and aliphatic H atoms at Uiso(H) = 1.2Ueq(C).

Figures

Fig. 1.
The molecular structure of title compound, showing 30% probability displacement ellipsoids.
Fig. 2.
The packing diagram of title compound showing N—H···π interaction

Crystal data

C20H19F2NOZ = 2
Mr = 327.36F(000) = 344
Triclinic, P1Dx = 1.327 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.4699 (3) ÅCell parameters from 3420 reflections
b = 10.6621 (4) Åθ = 2.5–27.4°
c = 10.7131 (4) ŵ = 0.10 mm1
α = 78.027 (2)°T = 298 K
β = 78.946 (2)°Block, colourless
γ = 87.201 (2)°0.42 × 0.38 × 0.12 mm
V = 819.16 (5) Å3

Data collection

Bruker APEXII CCD area-detector diffractometer3913 independent reflections
Radiation source: fine-focus sealed tube2564 reflections with I > 2σ(I)
graphiteRint = 0.021
[var phi] and ω scansθmax = 28.5°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 1999)h = −9→9
Tmin = 0.960, Tmax = 0.989k = −14→14
11219 measured reflectionsl = −14→14

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.156H atoms treated by a mixture of independent and constrained refinement
S = 0.81w = 1/[σ2(Fo2) + (0.1P)2 + 0.2685P] where P = (Fo2 + 2Fc2)/3
3913 reflections(Δ/σ)max < 0.001
221 parametersΔρmax = 0.17 e Å3
0 restraintsΔρmin = −0.20 e Å3

Special details

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 takeninto account individually in the estimation of e.s.d.'s in distances, anglesand torsion angles; correlations between e.s.d.'s in cell parameters are onlyused 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)

xyzUiso*/Ueq
C10.2684 (2)0.16060 (16)0.96799 (14)0.0419 (4)
H10.34990.08690.95850.050*
C20.3813 (2)0.27242 (18)0.98432 (15)0.0481 (4)
H20.44080.24311.05940.058*
C30.2715 (3)0.39499 (18)1.00204 (17)0.0546 (5)
H3A0.16940.37301.07340.066*
H3B0.34850.45321.02610.066*
C40.1990 (3)0.46430 (18)0.88289 (19)0.0595 (5)
H4A0.16070.55020.89410.071*
H4B0.09250.41960.87580.071*
C50.3381 (3)0.47348 (18)0.75758 (18)0.0591 (5)
H5A0.42430.54030.75260.071*
H5B0.27550.49870.68470.071*
C60.4445 (2)0.34774 (19)0.74473 (16)0.0506 (4)
H60.54330.36510.66890.061*
C70.3290 (2)0.23549 (16)0.73240 (14)0.0431 (4)
H70.41010.16160.72340.052*
C80.5261 (2)0.3061 (2)0.86420 (17)0.0540 (5)
C90.1194 (2)0.12155 (15)1.08599 (14)0.0397 (4)
C10−0.0618 (2)0.15942 (16)1.08968 (16)0.0463 (4)
H10−0.09710.20741.01530.056*
C11−0.1906 (3)0.12692 (19)1.20224 (18)0.0560 (5)
H11−0.31110.15351.20260.067*
C12−0.1423 (3)0.05585 (19)1.31351 (17)0.0595 (5)
H12−0.22940.03551.38910.071*
C130.0352 (3)0.01505 (18)1.31262 (16)0.0569 (5)
H130.0693−0.03471.38660.068*
C140.1613 (2)0.04921 (16)1.20018 (15)0.0470 (4)
C150.2390 (2)0.26888 (15)0.61458 (14)0.0415 (4)
C160.3352 (2)0.25928 (19)0.49306 (16)0.0524 (4)
C170.2607 (3)0.2853 (2)0.38267 (16)0.0638 (5)
H170.33060.27670.30310.077*
C180.0817 (3)0.3240 (2)0.39162 (17)0.0641 (5)
H180.02890.34190.31800.077*
C19−0.0185 (3)0.3362 (2)0.50969 (18)0.0586 (5)
H19−0.13960.36300.51580.070*
C200.0587 (2)0.30888 (17)0.62043 (15)0.0483 (4)
H20−0.01160.31760.69980.058*
F10.33764 (16)0.01112 (12)1.20093 (11)0.0726 (4)
F20.51212 (16)0.21980 (16)0.48284 (11)0.0853 (4)
N10.19010 (18)0.19950 (13)0.85064 (11)0.0397 (3)
O10.68765 (18)0.30314 (19)0.86537 (14)0.0831 (5)
H1A0.129 (3)0.1358 (19)0.8399 (17)0.050 (5)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0392 (9)0.0502 (9)0.0351 (7)0.0105 (7)−0.0090 (6)−0.0071 (6)
C20.0358 (9)0.0718 (12)0.0383 (8)−0.0009 (8)−0.0129 (7)−0.0095 (7)
C30.0525 (11)0.0631 (11)0.0508 (9)−0.0147 (8)−0.0022 (8)−0.0209 (8)
C40.0605 (12)0.0489 (10)0.0693 (12)0.0008 (8)−0.0086 (9)−0.0159 (9)
C50.0642 (13)0.0551 (11)0.0563 (10)−0.0146 (9)−0.0138 (9)−0.0020 (8)
C60.0322 (9)0.0761 (12)0.0394 (8)−0.0063 (8)−0.0011 (6)−0.0058 (8)
C70.0383 (9)0.0550 (9)0.0346 (7)0.0099 (7)−0.0049 (6)−0.0096 (6)
C80.0326 (9)0.0790 (13)0.0511 (9)−0.0024 (8)−0.0082 (7)−0.0138 (9)
C90.0453 (9)0.0394 (8)0.0346 (7)0.0037 (6)−0.0101 (6)−0.0068 (6)
C100.0446 (10)0.0486 (9)0.0438 (8)0.0023 (7)−0.0109 (7)−0.0035 (7)
C110.0452 (10)0.0608 (11)0.0579 (10)−0.0033 (8)−0.0012 (8)−0.0098 (8)
C120.0694 (14)0.0598 (11)0.0437 (9)−0.0146 (10)0.0050 (8)−0.0087 (8)
C130.0797 (14)0.0511 (10)0.0377 (8)−0.0041 (9)−0.0130 (8)−0.0011 (7)
C140.0542 (11)0.0456 (9)0.0423 (8)0.0080 (7)−0.0159 (7)−0.0064 (7)
C150.0440 (9)0.0463 (9)0.0330 (7)−0.0007 (7)−0.0048 (6)−0.0073 (6)
C160.0469 (10)0.0682 (12)0.0413 (8)−0.0012 (8)−0.0013 (7)−0.0152 (8)
C170.0727 (14)0.0846 (14)0.0337 (8)−0.0122 (11)−0.0027 (8)−0.0149 (8)
C180.0746 (14)0.0775 (14)0.0419 (9)−0.0108 (11)−0.0218 (9)−0.0032 (9)
C190.0521 (11)0.0728 (13)0.0504 (10)0.0027 (9)−0.0182 (8)−0.0036 (8)
C200.0469 (10)0.0581 (10)0.0377 (8)0.0034 (8)−0.0067 (7)−0.0068 (7)
F10.0669 (8)0.0863 (9)0.0600 (7)0.0256 (6)−0.0257 (6)0.0019 (6)
F20.0542 (7)0.1445 (13)0.0570 (7)0.0195 (7)0.0026 (5)−0.0363 (7)
N10.0402 (8)0.0478 (8)0.0312 (6)−0.0022 (6)−0.0083 (5)−0.0062 (5)
O10.0315 (8)0.1455 (16)0.0696 (9)−0.0015 (8)−0.0105 (6)−0.0143 (9)

Geometric parameters (Å, °)

C1—N11.4617 (19)C9—C141.386 (2)
C1—C91.516 (2)C9—C101.389 (2)
C1—C21.551 (3)C10—C111.384 (2)
C1—H10.9800C10—H100.9300
C2—C81.506 (2)C11—C121.374 (3)
C2—C31.535 (3)C11—H110.9300
C2—H20.9800C12—C131.374 (3)
C3—C41.518 (3)C12—H120.9300
C3—H3A0.9700C13—C141.374 (2)
C3—H3B0.9700C13—H130.9300
C4—C51.520 (3)C14—F11.361 (2)
C4—H4A0.9700C15—C161.382 (2)
C4—H4B0.9700C15—C201.386 (2)
C5—C61.542 (3)C16—F21.358 (2)
C5—H5A0.9700C16—C171.373 (3)
C5—H5B0.9700C17—C181.371 (3)
C6—C81.498 (2)C17—H170.9300
C6—C71.550 (3)C18—C191.368 (3)
C6—H60.9800C18—H180.9300
C7—N11.4703 (19)C19—C201.388 (2)
C7—C151.513 (2)C19—H190.9300
C7—H70.9800C20—H200.9300
C8—O11.208 (2)N1—H1A0.88 (2)
N1—C1—C9110.56 (13)O1—C8—C6124.57 (16)
N1—C1—C2109.45 (13)O1—C8—C2123.79 (16)
C9—C1—C2110.71 (13)C6—C8—C2111.61 (14)
N1—C1—H1108.7C14—C9—C10116.13 (14)
C9—C1—H1108.7C14—C9—C1120.38 (14)
C2—C1—H1108.7C10—C9—C1123.42 (13)
C8—C2—C3107.64 (15)C11—C10—C9121.07 (15)
C8—C2—C1107.86 (14)C11—C10—H10119.5
C3—C2—C1114.94 (14)C9—C10—H10119.5
C8—C2—H2108.8C12—C11—C10120.71 (18)
C3—C2—H2108.8C12—C11—H11119.6
C1—C2—H2108.8C10—C11—H11119.6
C4—C3—C2114.55 (14)C13—C12—C11119.71 (16)
C4—C3—H3A108.6C13—C12—H12120.1
C2—C3—H3A108.6C11—C12—H12120.1
C4—C3—H3B108.6C14—C13—C12118.66 (16)
C2—C3—H3B108.6C14—C13—H13120.7
H3A—C3—H3B107.6C12—C13—H13120.7
C3—C4—C5113.26 (16)F1—C14—C13118.33 (15)
C3—C4—H4A108.9F1—C14—C9117.96 (15)
C5—C4—H4A108.9C13—C14—C9123.70 (16)
C3—C4—H4B108.9C16—C15—C20116.11 (15)
C5—C4—H4B108.9C16—C15—C7120.57 (15)
H4A—C4—H4B107.7C20—C15—C7123.31 (13)
C4—C5—C6114.00 (15)F2—C16—C17118.29 (15)
C4—C5—H5A108.8F2—C16—C15118.14 (15)
C6—C5—H5A108.8C17—C16—C15123.57 (17)
C4—C5—H5B108.8C18—C17—C16118.98 (16)
C6—C5—H5B108.8C18—C17—H17120.5
H5A—C5—H5B107.6C16—C17—H17120.5
C8—C6—C5107.17 (15)C19—C18—C17119.53 (17)
C8—C6—C7107.89 (15)C19—C18—H18120.2
C5—C6—C7115.27 (14)C17—C18—H18120.2
C8—C6—H6108.8C18—C19—C20120.73 (18)
C5—C6—H6108.8C18—C19—H19119.6
C7—C6—H6108.8C20—C19—H19119.6
N1—C7—C15110.02 (13)C15—C20—C19121.07 (15)
N1—C7—C6109.92 (13)C15—C20—H20119.5
C15—C7—C6111.89 (13)C19—C20—H20119.5
N1—C7—H7108.3C1—N1—C7112.94 (12)
C15—C7—H7108.3C1—N1—H1A109.7 (12)
C6—C7—H7108.3C7—N1—H1A106.9 (12)
N1—C1—C2—C8−57.90 (16)C9—C10—C11—C12−0.1 (3)
C9—C1—C2—C8179.98 (13)C10—C11—C12—C13−0.9 (3)
N1—C1—C2—C362.16 (17)C11—C12—C13—C141.4 (3)
C9—C1—C2—C3−59.96 (17)C12—C13—C14—F1178.41 (16)
C8—C2—C3—C452.2 (2)C12—C13—C14—C9−0.9 (3)
C1—C2—C3—C4−68.03 (19)C10—C9—C14—F1−179.44 (15)
C2—C3—C4—C5−43.7 (2)C1—C9—C14—F1−2.3 (2)
C3—C4—C5—C644.4 (2)C10—C9—C14—C13−0.1 (3)
C4—C5—C6—C8−53.8 (2)C1—C9—C14—C13177.01 (16)
C4—C5—C6—C766.3 (2)N1—C7—C15—C16−155.80 (16)
C8—C6—C7—N156.93 (17)C6—C7—C15—C1681.71 (19)
C5—C6—C7—N1−62.77 (17)N1—C7—C15—C2023.5 (2)
C8—C6—C7—C15179.48 (13)C6—C7—C15—C20−98.96 (18)
C5—C6—C7—C1559.78 (17)C20—C15—C16—F2−179.68 (16)
C5—C6—C8—O1−113.1 (2)C7—C15—C16—F2−0.3 (3)
C7—C6—C8—O1122.2 (2)C20—C15—C16—C17−0.9 (3)
C5—C6—C8—C264.94 (19)C7—C15—C16—C17178.47 (18)
C7—C6—C8—C2−59.75 (19)F2—C16—C17—C18179.38 (18)
C3—C2—C8—O1113.9 (2)C15—C16—C17—C180.6 (3)
C1—C2—C8—O1−121.6 (2)C16—C17—C18—C190.1 (3)
C3—C2—C8—C6−64.20 (19)C17—C18—C19—C20−0.4 (3)
C1—C2—C8—C660.36 (19)C16—C15—C20—C190.5 (3)
N1—C1—C9—C14162.27 (15)C7—C15—C20—C19−178.81 (17)
C2—C1—C9—C14−76.27 (19)C18—C19—C20—C150.1 (3)
N1—C1—C9—C10−20.8 (2)C9—C1—N1—C7−178.60 (13)
C2—C1—C9—C10100.64 (18)C2—C1—N1—C759.20 (17)
C14—C9—C10—C110.6 (2)C15—C7—N1—C1177.51 (13)
C1—C9—C10—C11−176.38 (16)C6—C7—N1—C1−58.84 (17)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1A···Cgi0.90 (4)2.72 (2)3.58 (16)167.3 (19)

Symmetry codes: (i) −x, −y, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BQ2146).

References

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