2,4,6,8-Tetra­kis(2-fluoro­phen­yl)-3,7-diaza­bicyclo­[3.3.1]nonan-9-one

Dong Ho Park; V Ramkumar; P Parthiban

doi:10.1107/S1600536812051574

. 2013 Jan 4;69(Pt 2):o179. doi: 10.1107/S1600536812051574

2,4,6,8-Tetrakis(2-fluorophenyl)-3,7-diazabicyclo[3.3.1]nonan-9-one

Dong Ho Park ^a, V Ramkumar ^b, P Parthiban ^a,^*

PMCID: PMC3569241 PMID: 23424464

Abstract

The title compound, C₃₁H₂₄F₄N₂O, exists in a chair–boat conformation with an equatorial orientation of the 2-fluorophenyl groups on both sides of the secondary amino group of the chair form. The benzene rings in the ‘chair’ part are inclined to each other at 19.4 (1)°, while the equivalent angle between the benzene rings in the ‘boat’ part is 75.6 (1)°. One F atom was treated as disordered over two positions in a 0.838 (4):0.162 (4) ratio. In the crystal, N—H⋯O hydrogen bonds link the molecules into chains along [001] and these chains are held together via weak N—H⋯F and C—H⋯F interactions.

Related literature

For the synthesis and stereochemistry of 3,7-diazabicyclo[3.3.1]nonan-9-ones, see: Parthiban et al. (2008 ▶). For the biological activity of 3,7-diazabicyclo[3.3.1]nonan-9-one derivatives and related structures, see: Park et al. (2012 ▶); Parthiban et al. (2009 ▶, 2010 ▶); Asakawa (1995 ▶); Jeyaraman & Avila (1981 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₃₁H₂₄F₄N₂O
M _r = 516.52
Monoclinic,
a = 12.5610 (11) Å
b = 15.9118 (13) Å
c = 13.0221 (8) Å
β = 103.207 (3)°
V = 2533.9 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.45 × 0.35 × 0.22 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.955, T _max = 0.978
18116 measured reflections
5466 independent reflections
3571 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.163
S = 1.05
5466 reflections
361 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(33.4KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812051574/cv5368sup1.cif

e-69-0o179-sup1.cif^{(33.4KB, cif)}

Click here for additional data file.^{(267.7KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812051574/cv5368Isup2.hkl

e-69-0o179-Isup2.hkl^{(267.7KB, hkl)}

Click here for additional data file.^{(9.4KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812051574/cv5368Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1ⁱ	0.86 (2)	2.26 (2)	3.119 (2)	175.2 (19)
N2—H2N⋯F1ⁱⁱ	0.92 (2)	2.46 (2)	3.332 (2)	158.4 (17)
C22—H22⋯F4ⁱⁱⁱ	0.93	2.52	3.345 (3)	148

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

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

supplementary crystallographic information

Comment

The Lupin alkaloids contain the 3,7-diazabicyclo[3.3.1]nonan-9-one nucleus, displaying various biological actions (Parthiban et al., 2009, 2010; Asakawa, 1995; Jeyaraman & Avila, 1981). Since the biological actions mainly depend on the stereochemistry of the molecules, we examined the title compound, (I), to explore its stereochemistry in the solid-state.

In (I) (Fig. 1), the piperidone ring N1—C1—C2—C7—C5—C6 adopts a chair conformation, according to Cremer & Pople (1975). The total puckering amplitude Q_T is 0.623 (2) Å, and the phase angle θ is 2.7 (3)°. The piperidone ring N2—C3—C2—C7—C5—C4 adopts a boat conformation with Q_T = 0.799 (2) and θ = 90.38 (14)°. The 2-fluorophenyl groups attached to the 'chair' piperidone ring are in equatoril position with the torsion angles C7—C2—C1—C8 = 179.04 (19)° and C26—C6—C5—C7 = 176.67 (19)°. The 2-fluorophenyl groups attached to the 'boat' piperidone ring have the following torsion angles - C7—C2—C3—C14 = 116.8 (2)° and C20—C4—C5—C7 = -122.5 (2)°. The benzene rings of the 2-fluorophenyl group on the chair form piperidone are inclined to each other at an angle of 19.44 (3)°, whereas, the same attached on the boat form are inclined to each other at an angle of 74.55 (5)°. In one of the 2-fluorophenyl groups, the F atom is disordered in two positions in a ratio 0.838 (4):0.162 (4). On the basis of the above analysis, it is concluded that the title compound exists in the chair-boat conformation with an equatorial orientation of the 2-fluorophenyl groups on both sides of the secondary amino group of the piperidone in the chair conformation.

In the crystal, intermolecular N—H···O hydrogen bonds (Table 1) link the molecules into chains in [001], and these chains held together via weak N—H···F and C—H···F interactions (Table 1).

Experimental

The 2,4,6,8-tetrakis(2-fluorophenyl)-3,7-diazabicyclo[3.3.1] nonan-9-one was synthesized by successive Mannich condensations in one-pot, using 2-fluorobenzaldehyde (0.2 mol, 21 ml), acetone (0.05 mol, 3.7 ml) and ammonium acetate (0.1 mol, 7.7 g) in a 50 ml of absolute ethanol (Parthiban et al., 2008). The mixture was gently warmed on a hot plate at 303 K (30° C) with moderate stirring till the complete consumption of the starting materials, which was monitored by TLC. At the end, the crude 3,7-diazabicycle was separated by filtration and gently washed with 1:5 cold ethanol-ether mixture. The X-ray diffraction quality crystals of pure 2,4,6,8- tetrakis(2-fluorophenyl)-3,7-diazabicyclo[3.3.1]nonan-9-one was obtained by slow evaporation from ethanol.