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Acta Crystallogr Sect E Struct Rep Online. 2010 March 1; 66(Pt 3): o545.
Published online 2010 February 6. doi:  10.1107/S1600536810004095
PMCID: PMC2983554

2,4-Bis(4-chloro­phen­yl)-1-methyl-3-aza­bicyclo­[3.3.1]nonan-9-one

Abstract

The title compound, C21H21Cl2NO, exists in a twin-chair conformation with an equatorial orientation of the 4-chloro­phenyl groups on both sides of the secondary amino group; the dihedral angle between the 4-chloro­phenyl rings is 36.58 (2)°. The crystal packing is stabilized by an inter­molecular N—H(...)O hydrogen bond and a weak Cl(...)Cl [3.4331 (9) Å] inter­action.

Related literature

For the synthesis and biological activity of 3-aza­bicyclo­[3.3.1] nonan-9-ones, see: Parthiban et al. (2009 [triangle]); Hardick et al. (1996 [triangle]); Jeyaraman & Avila (1981 [triangle]). For the structure of the non-methyl­ated analog of the title compound, see: Parthiban et al. (2009a [triangle]). For related structures with similar conformations, see: Parthiban et al. (2009b [triangle], 2010 [triangle]). For a related structure with chair–boat conformation, see: Smith-Verdier et al. (1983 [triangle]). For a related structure with boat–boat conformation, see: Padegimas & Kovacic (1972 [triangle]). For ring puckering and asymmetry parameters, see: Cremer & Pople (1975 [triangle]); Nardelli (1983 [triangle]). Scheme: resolution poor

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Object name is e-66-0o545-scheme1.jpg

Experimental

Crystal data

  • C21H21Cl2NO
  • M r = 374.29
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o545-efi1.jpg
  • a = 28.4515 (14) Å
  • b = 7.0380 (3) Å
  • c = 21.2771 (12) Å
  • β = 117.148 (4)°
  • V = 3791.2 (3) Å3
  • Z = 8
  • Mo Kα radiation
  • μ = 0.35 mm−1
  • T = 298 K
  • 0.58 × 0.42 × 0.18 mm

Data collection

  • Bruker APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 1999 [triangle]) T min = 0.822, T max = 0.940
  • 24985 measured reflections
  • 4661 independent reflections
  • 3149 reflections with I > 2σ(I)
  • R int = 0.033

Refinement

  • R[F 2 > 2σ(F 2)] = 0.045
  • wR(F 2) = 0.125
  • S = 1.02
  • 4661 reflections
  • 231 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.36 e Å−3
  • Δρmin = −0.43 e Å−3

Data collection: APEX2 (Bruker, 2004 [triangle]); cell refinement: APEX2 and SAINT-Plus (Bruker, 2004 [triangle]); data reduction: SAINT-Plus and XPREP (Bruker, 2004 [triangle]); 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]) and Mercury (Macrae et al., 2006 [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/S1600536810004095/hb5322sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810004095/hb5322Isup2.hkl

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

Acknowledgments

This work was supported by the Corporate-affiliated Research Institute of Academic–Industrial–Institutional Cooperation Improvement Business No. S7080008110. The authors acknowledge the Department of Chemistry, IIT Madras, for the X-ray data collection.

supplementary crystallographic information

Comment

3-Azabicyclo[3.3.1]nonanes are an important class of heterocyclic compounds due to their broad spectrum of biological activities such as antibacterial, antifungal, analgesic, antogonistic, anti-inflammatory, local anesthetic and hypotensive activity, and their presence in a wide variety of naturally occurring diterpenoid/norditerpenoid alkaloids (Parthiban et al., 2009; Hardick et al., 1996; Jeyaraman & Avila, 1981). As stereochemistry plays a vital role in biological activities, it is essential to establish the stereochemistry of the synthesized bio-active molecules. Owing to the diverse possibilities in the conformation of the 3-azabicycle such as chair-chair (Parthiban et al., 2009b & 2010), chair-boat (Smith-Verdier et al., 1983) and boat-boat (Padegimas & Kovacic, 1972), the present crystal study was undertaken to examine the stereochemistry of the synthesized 2,4-bis(4-chlorophenyl)-1-methyl-3-azabicyclo[3.3.1]nonan-9-one.

The crystallographic analysis of the title compound shows that the piperidine ring adopts a near ideal chair conformation. The total puckering amplitude QT is 0.587 (2)Å and the phase angle θ is 1.8 (2)° (Cremer & Pople, 1975). The smallest displacement asymmetry parameters being q2 and q3 are 0.022 (2)Å and 0.587 (2) Å, respectively (Nardelli, 1983). The deviation of ring atoms C8 and N1 from the C1/C2/C6/C7 plane by 0.677 (3)Å and -0.642 (3) Å, respectively.

The crystallographic analysis of the title compound suggests that the cyclohexane ring deviates from the ideal chair conformation. The total puckering amplitude QT is 0.573 (2)Å and the phase angle θ is 13.8 (2)° (Cremer & Pople, 1975). The smallest displacement asymmetry parameters being q2 and q3 are 0.134 (2)Å and 0.556 (2) Å, respectively (Nardelli, 1983). The deviation of ring atoms C4 and C8 from the C2/C3/C5/C6 plane by -0.554 (4)Å and 0.723 (2) Å, respectively.

According to the crystallogrphic analysis, the title compound, C21H21Cl2N O, exists in a twin-chair conformation with an equatorial orientation of the para-chlorophenyl groups on both sides of the secondary amino group.

In the title compound, the para-chlorophenyl rings are orientated at an angle of 36.58 (2)° with respect to one another, whereas in its non-methyl analog, 2,4-bis(4-chlorophenyl)-3- azabicyclo[3.3.1]nonan-9-one, the angle is 31.33 (3)°. The crystal structure of the title compound is stabilized by an intermolecular N—H···O interaction and a weak Cl—Cl interaction [Cl···Cl = 3.43 Å]. Though similar interactions observed in the non-methyl analog, the hydrogen bond geometries such as distance and angle of N1—H1···O1 [respectively, 3.1202Å and 160.2 (18)°] are comparatively lower than the title compound (Table 1).

In the title compound, the torsion angles of C1—C2—C8—C9 and C6—C7—C8—C16 are -178.85 (4)° and -179.35 (4)°, respectively (in the non-methyl analog of the title compound, they are -177.88 (4)° and -179.01 (4)°).

Experimental

The 1-methyl-2,4-bis(4-chlorophenyl)-3-azabicyclo[3.3.1]nonan-9-one was synthesized by a modified Mannich reaction in one-pot, using para-chlorobenzaldehyde (0.1 mol, 14.06 g), 2-methylcyclohexanone (0.05 mol, 5.61 g/6.07 ml) and ammonium acetate (0.075 mol, 5.78 g) in 50 ml of absolute ethanol. The mixture was gently warmed on a hot plate with stirring and continued at 303-308 K (30-35° C) till completion of the reaction. The progress was monitered by TLC. After all starting material was used up, the crude 3-azabicyclononan-9-one was separated by filtration and washed with a 1:5 ethanol-ether mixture, till the solid becomes colorless. Colourless blocks of (I) were obtained by slow evoporation from ethanol.

Refinement

The nitrogen H atom was 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, methylene C—H = 0.97 Å, methine C—H = 0.98 Å and methyl C—H = 0.96 Å . The displacement parameters were set for phenyl, methylene and aliphatic H atoms at Uiso(H) = 1.2Ueq(C) and for methyl H atoms atUiso(H) = 1.5Ueq(C)

Figures

Fig. 1.
The molecular structure of (I) with atoms represented with 30% probability ellipsoids.
Fig. 2.
Packing diagram for (I) showing the N—H···O and Cl···Cl interactions.

Crystal data

C21H21Cl2NOF(000) = 1568
Mr = 374.29Dx = 1.312 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 7359 reflections
a = 28.4515 (14) Åθ = 2.5–27.3°
b = 7.0380 (3) ŵ = 0.35 mm1
c = 21.2771 (12) ÅT = 298 K
β = 117.148 (4)°Rectangular block, colourless
V = 3791.2 (3) Å30.58 × 0.42 × 0.18 mm
Z = 8

Data collection

Bruker APEXII CCD diffractometer4661 independent reflections
Radiation source: fine-focus sealed tube3149 reflections with I > 2σ(I)
graphiteRint = 0.033
phi and ω scansθmax = 28.2°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 1999)h = −36→37
Tmin = 0.822, Tmax = 0.940k = −8→9
24985 measured reflectionsl = −28→27

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) = 0.125H atoms treated by a mixture of independent and constrained refinement
S = 1.02w = 1/[σ2(Fo2) + (0.0487P)2 + 3.2087P] where P = (Fo2 + 2Fc2)/3
4661 reflections(Δ/σ)max = 0.001
231 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = −0.43 e Å3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)are estimated using the full covariance matrix. The cell esds are takeninto account individually in the estimation of esds in distances, anglesand torsion angles; correlations between esds in cell parameters are onlyused when they are defined by crystal symmetry. An approximate (isotropic)treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR andgoodness of fit S are based on F2, conventional R-factors R are basedon F, with F set to zero for negative F2. The threshold expression ofF2 > σ(F2) is used only for calculating R-factors(gt) etc. and isnot relevant to the choice of reflections for refinement. R-factors basedon 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
C10.17656 (7)0.4818 (2)0.98420 (9)0.0357 (4)
H10.21310.48890.99160.043*
C20.15724 (7)0.6894 (2)0.98539 (10)0.0393 (4)
C30.09894 (8)0.7068 (3)0.97191 (11)0.0501 (5)
H3A0.09490.63541.00820.060*
H3B0.09190.83910.97720.060*
C40.05740 (8)0.6377 (3)0.90001 (12)0.0556 (5)
H4A0.02280.67900.89290.067*
H4B0.05750.49990.89930.067*
C50.06735 (8)0.7126 (3)0.83970 (11)0.0559 (5)
H5A0.05640.84460.83110.067*
H5B0.04560.64160.79720.067*
C60.12516 (8)0.6988 (3)0.85398 (10)0.0450 (4)
H60.12920.76940.81710.054*
C70.14595 (7)0.4935 (2)0.85650 (9)0.0395 (4)
H70.18260.50100.86440.047*
C80.15846 (7)0.7924 (2)0.92360 (10)0.0413 (4)
C90.17610 (7)0.3620 (2)1.04297 (9)0.0376 (4)
C100.22206 (8)0.3354 (3)1.10561 (10)0.0478 (5)
H100.25370.38461.10990.057*
C110.22168 (9)0.2369 (3)1.16196 (10)0.0537 (5)
H110.25280.21961.20350.064*
C120.17493 (9)0.1654 (3)1.15562 (10)0.0487 (5)
C130.12899 (8)0.1845 (3)1.09386 (11)0.0504 (5)
H130.09760.13251.08970.061*
C140.12984 (7)0.2817 (3)1.03794 (10)0.0443 (4)
H140.09880.29380.99600.053*
C150.19367 (9)0.7841 (3)1.05543 (11)0.0562 (5)
H15A0.22980.76071.06620.084*
H15B0.18690.73281.09230.084*
H15C0.18720.91861.05190.084*
C160.11369 (7)0.3942 (3)0.78664 (10)0.0426 (4)
C170.11848 (10)0.4523 (3)0.72767 (12)0.0616 (6)
H170.14330.54450.73240.074*
C180.08692 (11)0.3752 (4)0.66173 (12)0.0692 (7)
H180.08980.41790.62220.083*
C190.05165 (8)0.2361 (3)0.65530 (10)0.0542 (5)
C200.04760 (9)0.1701 (4)0.71289 (12)0.0633 (6)
H200.02430.07190.70820.076*
C210.07852 (9)0.2507 (3)0.77862 (11)0.0571 (5)
H210.07540.20700.81780.068*
Cl10.17372 (3)0.04670 (9)1.22681 (3)0.0770 (2)
Cl20.01186 (2)0.13710 (11)0.57245 (3)0.0829 (2)
N10.14499 (6)0.3905 (2)0.91547 (8)0.0379 (3)
O10.18212 (6)0.94051 (19)0.92903 (8)0.0570 (4)
H1A0.1580 (8)0.278 (3)0.9181 (11)0.050 (6)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0365 (9)0.0322 (8)0.0378 (9)−0.0037 (7)0.0163 (7)−0.0053 (7)
C20.0433 (10)0.0310 (8)0.0429 (10)−0.0022 (7)0.0190 (8)−0.0065 (7)
C30.0534 (11)0.0426 (10)0.0625 (13)0.0049 (9)0.0335 (10)−0.0002 (9)
C40.0380 (10)0.0519 (12)0.0729 (15)0.0024 (9)0.0218 (10)0.0035 (10)
C50.0498 (11)0.0484 (11)0.0540 (12)0.0071 (9)0.0103 (10)0.0044 (10)
C60.0557 (11)0.0341 (9)0.0436 (10)−0.0041 (8)0.0212 (9)0.0039 (8)
C70.0442 (10)0.0363 (9)0.0395 (9)−0.0073 (7)0.0204 (8)−0.0038 (7)
C80.0413 (9)0.0289 (8)0.0556 (11)0.0005 (7)0.0239 (9)−0.0021 (8)
C90.0425 (9)0.0316 (8)0.0358 (9)−0.0020 (7)0.0153 (8)−0.0045 (7)
C100.0442 (10)0.0454 (10)0.0447 (11)−0.0050 (8)0.0123 (9)−0.0015 (8)
C110.0578 (12)0.0486 (11)0.0391 (10)−0.0002 (9)0.0086 (9)0.0007 (9)
C120.0700 (13)0.0355 (9)0.0435 (11)0.0047 (9)0.0286 (10)0.0030 (8)
C130.0528 (11)0.0438 (10)0.0589 (12)−0.0018 (9)0.0292 (10)0.0052 (9)
C140.0428 (10)0.0417 (10)0.0425 (10)−0.0033 (8)0.0143 (8)0.0022 (8)
C150.0680 (13)0.0418 (10)0.0543 (12)−0.0053 (10)0.0240 (11)−0.0157 (9)
C160.0498 (10)0.0395 (9)0.0400 (10)−0.0036 (8)0.0219 (8)−0.0034 (8)
C170.0870 (16)0.0565 (13)0.0506 (12)−0.0205 (12)0.0395 (12)−0.0065 (10)
C180.1041 (19)0.0679 (15)0.0417 (12)−0.0056 (14)0.0385 (13)−0.0044 (11)
C190.0510 (11)0.0640 (13)0.0403 (11)0.0042 (10)0.0146 (9)−0.0157 (10)
C200.0584 (13)0.0781 (16)0.0545 (13)−0.0249 (12)0.0268 (11)−0.0228 (12)
C210.0655 (13)0.0656 (13)0.0428 (11)−0.0235 (11)0.0270 (10)−0.0106 (10)
Cl10.1104 (5)0.0655 (4)0.0658 (4)0.0146 (3)0.0494 (4)0.0240 (3)
Cl20.0677 (4)0.1129 (6)0.0483 (3)0.0084 (4)0.0094 (3)−0.0332 (3)
N10.0474 (9)0.0284 (7)0.0358 (8)−0.0031 (6)0.0170 (7)−0.0040 (6)
O10.0632 (9)0.0357 (7)0.0738 (10)−0.0121 (6)0.0328 (8)−0.0032 (7)

Geometric parameters (Å, °)

C1—N11.469 (2)C10—C111.389 (3)
C1—C91.513 (2)C10—H100.9300
C1—C21.565 (2)C11—C121.370 (3)
C1—H10.9800C11—H110.9300
C2—C81.516 (3)C12—C131.373 (3)
C2—C151.527 (3)C12—Cl11.744 (2)
C2—C31.554 (3)C13—C141.382 (3)
C3—C41.524 (3)C13—H130.9300
C3—H3A0.9700C14—H140.9300
C3—H3B0.9700C15—H15A0.9600
C4—C51.529 (3)C15—H15B0.9600
C4—H4A0.9700C15—H15C0.9600
C4—H4B0.9700C16—C211.377 (3)
C5—C61.533 (3)C16—C171.384 (3)
C5—H5A0.9700C17—C181.386 (3)
C5—H5B0.9700C17—H170.9300
C6—C81.498 (3)C18—C191.363 (3)
C6—C71.553 (3)C18—H180.9300
C6—H60.9800C19—C201.364 (3)
C7—N11.460 (2)C19—Cl21.747 (2)
C7—C161.515 (2)C20—C211.389 (3)
C7—H70.9800C20—H200.9300
C8—O11.217 (2)C21—H210.9300
C9—C101.389 (3)N1—H1A0.87 (2)
C9—C141.391 (3)
N1—C1—C9110.30 (13)C10—C9—C14117.55 (17)
N1—C1—C2111.38 (14)C10—C9—C1120.56 (16)
C9—C1—C2111.78 (14)C14—C9—C1121.83 (16)
N1—C1—H1107.7C11—C10—C9121.37 (18)
C9—C1—H1107.7C11—C10—H10119.3
C2—C1—H1107.7C9—C10—H10119.3
C8—C2—C15111.32 (15)C12—C11—C10119.18 (18)
C8—C2—C3104.31 (15)C12—C11—H11120.4
C15—C2—C3109.74 (16)C10—C11—H11120.4
C8—C2—C1106.57 (14)C11—C12—C13121.07 (18)
C15—C2—C1109.68 (15)C11—C12—Cl1119.56 (16)
C3—C2—C1115.08 (14)C13—C12—Cl1119.36 (16)
C4—C3—C2115.70 (16)C12—C13—C14119.27 (19)
C4—C3—H3A108.4C12—C13—H13120.4
C2—C3—H3A108.4C14—C13—H13120.4
C4—C3—H3B108.4C13—C14—C9121.50 (18)
C2—C3—H3B108.4C13—C14—H14119.3
H3A—C3—H3B107.4C9—C14—H14119.3
C3—C4—C5112.12 (17)C2—C15—H15A109.5
C3—C4—H4A109.2C2—C15—H15B109.5
C5—C4—H4A109.2H15A—C15—H15B109.5
C3—C4—H4B109.2C2—C15—H15C109.5
C5—C4—H4B109.2H15A—C15—H15C109.5
H4A—C4—H4B107.9H15B—C15—H15C109.5
C4—C5—C6113.87 (16)C21—C16—C17118.09 (18)
C4—C5—H5A108.8C21—C16—C7122.73 (17)
C6—C5—H5A108.8C17—C16—C7119.16 (17)
C4—C5—H5B108.8C16—C17—C18121.1 (2)
C6—C5—H5B108.8C16—C17—H17119.5
H5A—C5—H5B107.7C18—C17—H17119.5
C8—C6—C5107.78 (16)C19—C18—C17119.4 (2)
C8—C6—C7108.41 (15)C19—C18—H18120.3
C5—C6—C7115.04 (15)C17—C18—H18120.3
C8—C6—H6108.5C18—C19—C20120.96 (19)
C5—C6—H6108.5C18—C19—Cl2119.73 (18)
C7—C6—H6108.5C20—C19—Cl2119.29 (18)
N1—C7—C16111.94 (14)C19—C20—C21119.4 (2)
N1—C7—C6109.61 (15)C19—C20—H20120.3
C16—C7—C6110.16 (15)C21—C20—H20120.3
N1—C7—H7108.3C16—C21—C20121.0 (2)
C16—C7—H7108.3C16—C21—H21119.5
C6—C7—H7108.3C20—C21—H21119.5
O1—C8—C6122.90 (18)C7—N1—C1113.28 (13)
O1—C8—C2123.91 (18)C7—N1—H1A109.6 (13)
C6—C8—C2113.12 (14)C1—N1—H1A106.6 (14)
N1—C1—C2—C8−54.97 (18)C2—C1—C9—C1479.6 (2)
C9—C1—C2—C8−178.85 (14)C14—C9—C10—C11−1.7 (3)
N1—C1—C2—C15−175.58 (15)C1—C9—C10—C11175.53 (17)
C9—C1—C2—C1560.54 (19)C9—C10—C11—C12−0.3 (3)
N1—C1—C2—C360.1 (2)C10—C11—C12—C132.1 (3)
C9—C1—C2—C3−63.8 (2)C10—C11—C12—Cl1−178.40 (15)
C8—C2—C3—C454.2 (2)C11—C12—C13—C14−1.7 (3)
C15—C2—C3—C4173.54 (17)Cl1—C12—C13—C14178.79 (15)
C1—C2—C3—C4−62.2 (2)C12—C13—C14—C9−0.5 (3)
C2—C3—C4—C5−46.7 (2)C10—C9—C14—C132.1 (3)
C3—C4—C5—C644.8 (2)C1—C9—C14—C13−175.09 (17)
C4—C5—C6—C8−52.9 (2)N1—C7—C16—C2113.9 (3)
C4—C5—C6—C768.2 (2)C6—C7—C16—C21−108.3 (2)
C8—C6—C7—N157.08 (19)N1—C7—C16—C17−167.77 (18)
C5—C6—C7—N1−63.6 (2)C6—C7—C16—C1770.0 (2)
C8—C6—C7—C16−179.33 (15)C21—C16—C17—C183.2 (4)
C5—C6—C7—C1660.0 (2)C7—C16—C17—C18−175.2 (2)
C5—C6—C8—O1−111.7 (2)C16—C17—C18—C19−1.9 (4)
C7—C6—C8—O1123.23 (19)C17—C18—C19—C20−1.0 (4)
C5—C6—C8—C265.39 (19)C17—C18—C19—Cl2−179.72 (19)
C7—C6—C8—C2−59.72 (19)C18—C19—C20—C212.4 (4)
C15—C2—C8—O1−5.7 (3)Cl2—C19—C20—C21−178.89 (18)
C3—C2—C8—O1112.63 (19)C17—C16—C21—C20−1.8 (3)
C1—C2—C8—O1−125.20 (18)C7—C16—C21—C20176.5 (2)
C15—C2—C8—C6177.33 (16)C19—C20—C21—C16−0.9 (4)
C3—C2—C8—C6−64.39 (18)C16—C7—N1—C1179.17 (14)
C1—C2—C8—C657.77 (19)C6—C7—N1—C1−58.29 (19)
N1—C1—C9—C10137.96 (17)C9—C1—N1—C7−176.97 (14)
C2—C1—C9—C10−97.55 (19)C2—C1—N1—C758.32 (19)
N1—C1—C9—C14−44.9 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.87 (2)2.45 (2)3.309 (2)170.2 (18)

Symmetry codes: (i) x, y−1, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB5322).

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