2,3,6-Triphenyl-piperidin-4-one.

Abstract

In the title mol-ecule, C(23)H(21)NO, the piperidine ring adopts a chair conformation, with the N and carbonyl C atoms as flaps, which deviate on either side of the chair by -0.706 (3) and 0.494 (3) Å, respectively. All three phenyl rings are in equatorial positions on the piperidine ring, making angles with the puckering plane of 73.5 (1), 73.1 (1) and 67.2 (1)°. Though there is no classical hydrogen bonding, the crystal is stabilized by inter-molecular C-H⋯π contacts and π-π stacking inter-actions involving phenyl rings [centroid-centroid distance = 4.424 (2) Å].

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2,3,6-Triphenylpiperidin-4-one
N. Mahalakshmi Lavanya,aR. Anitha,aS. Athimoolam,a
P. Alex Rajaband P. L. Nilantha Lakshmanc*
aDepartment of Physics, Kalasalingam University, Krishnan koil 626 190, Tamil
Nadu, India,bDepartment of Organic Chemistry, Madurai Kamaraj University,
Madurai 625 021, India, andcDepartment of Food Science and Technology, Faculty
of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya 81100, Sri Lanka
Correspondence e-mail: nilanthalakshman@yahoo.co.uk
Received 6 August 2009; accepted 3 September 2009
Key indicators: single-crystal X-ray study; T = 293 K; mean ?(C–C) = 0.003 A ˚;
R factor = 0.038; wR factor = 0.125; data-to-parameter ratio = 13.8.
In the title molecule, C23H21NO, the piperidine ring adopts a
chair conformation, with the N and carbonyl C atoms as flaps,
which deviate on either side of the chair by ?0.706 (3) and
0.494 (3) A˚, respectively. All three phenyl rings are in
equatorial positions on the piperidine ring, making angles
with the puckering plane of 73.5 (1), 73.1 (1) and 67.2 (1)?.
Though there is no classical hydrogen bonding, the crystal is
stabilized by intermolecular C—H???? contacts and ?–?
stacking interactions involving phenyl rings [centroid–
centroid distance = 4.424 (2) A˚].
Related literature
For the biological importance of piperidone and its deriva-
tives, see: Robinson (1973). For similar structures, see: Mobio
et al. (1989); Jia et al. (1989a,b); Cheer et al. (1984); Sekar et al.
(1990, 1993); Sukumar et al. (1994); Ompraba et al. (2003). For
puckering analysis, see: Cremer & Pople (1975).
Experimental
Crystal data
C23H21NO
Mr= 327.41
Monoclinic, P21=c
a = 12.144 (4) A˚
b = 5.998 (2) A˚
c = 25.127 (7) A˚
? = 94.55 (2)?
V = 1824.3 (9) A˚3
Z = 4
Mo K? radiation
? = 0.07 mm?1
T = 293 K
0.21 ? 0.18 ? 0.15 mm
Data collection
Nonius MACH3 sealed-tube
diffractometer
Absorption correction: scan
(North et al., 1968)
Tmin= 0.914, Tmax= 1.000
3552 measured reflections
3193 independent reflections
1906 reflections with I > 2?(I)
Rint= 0.029
3 standard reflections
frequency: 60 min
intensity decay: <1%
Refinement
R[F2> 2?(F2)] = 0.038
wR(F2) = 0.125
S = 1.02
3193 reflections
231 parameters
H atoms treated by a mixture of
independent and constrained
refinement
??max= 0.16 e A˚?3
??min= ?0.16 e A˚?3
Table 1
Hydrogen-bond geometry (A˚,?).
D—H???A
C14—H14???Cg2i
C35—H35???Cg3ii
Symmetry codes: (i) ?x þ 1;?y þ 1;?z; (ii) ?x;y ?1
D—HH???AD???AD—H???A
0.93
0.93
3.37
3.37
4.111 (4)
4.120 (3)
139
138
2;?z þ1
2.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell
refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms &
Wocadlo, 1995); program(s) used to solve structure: SHELXTL
(Sheldrick, 2008); program(s) used to refine structure: SHELXTL;
molecular graphics: PLATON (Spek, 2009); software used to prepare
material for publication: SHELXTL.
NML, RA and SA sincerely thank the Vice-Chancellor and
management of Kalasalingam University, Anand Nagar and
Krishnan Koil, for their support and encouragement.
Supplementary data and figures for this paper are available from the
IUCr electronic archives (Reference: BH2244).
References
Cheer,C. J., Cosgrove, J. P. & Vittimberga, B. M. (1984). Acta Cryst.C40, 1474–
1475.
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358.
Enraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Nether-
lands.
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg. Germany.
Jia, Z., Quail, J. W., Arora, V. K. & Dimmock, J. R. (1989a). Acta Cryst. C45,
285–289.
Jia, Z., Quail, J. W., Arora, V. K. & Dimmock, J. R. (1989b). Acta Cryst. C45,
1117–1118.
Mobio, I. G., Soldatenkov, A. T., Fedorov, V. O., Ageev, E. A., Sergeeva, N. D.,
Lin, S., Stashenko, E. E., Prostakov, N. S. & Andreeva, E. I. (1989). Khim.
Farm. Zh. 23, 421–427.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–
359.
Ompraba, G., Srinivasan, M., Perumal, S., Sekar, K., Choudhury, A. R., Guru
Row, T. N. & Rafi, Z. A. (2003). Cryst. Res. Technol. 38, 918–921.
Robinson, O. P. W. (1973). Postgrad. Med. J. (Suppl.), 49, 9–13.
Sekar, K., Parthasarathy, S. & Radhakrishnan, T. R. (1990). Acta Cryst. C46,
1338–1340.
Sekar, K., Parthasarathy, S. & Radhakrishnan, T. R. (1993). Acta Cryst. C49,
93–95.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Spek, A. L. (2009). Acta Cryst. D65, 148–155.
Sukumar,N., Ponnuswamy,M. N.,Thenmozhiyal, J. C. &Jeyaraman,R. (1994).
Bull. Chem. Soc. Jpn, 67, 1069–1073.
organic compounds
o2430
Lavanya et al.
doi:10.1107/S1600536809035673
Acta Cryst. (2009). E65, o2430
Acta Crystallographica Section E
Structure Reports
Online
ISSN 1600-5368

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supplementary materials
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Acta Cryst. (2009). E65, o2430 [ doi:10.1107/S1600536809035673 ]
2,3,6-Triphenylpiperidin-4-one
N. M. Lavanya, R. Anitha, S. Athimoolam, P. A. Raja and P. L. N. Lakshman
Comment
Piperidones possess a variety of biological activities including antihistaminic agents, oral anesthetics, narcotic analgesics,
tranquillizers, hypotensive agents, cytotoxic and anti-cancer (Robinson, 1973). Piperidine with 2,6-substitutions have been
found to have bactericidal, herbicidal and fungicidal activities (Mobio et al., 1989). The medicinal and fungicidal properties
of the piperidones are determined by the nature and position of substituents attached to the ring. Piperidones with different
substitutions have been reported earlier (Jia et al., 1989a, 1989b; Cheer et al., 1984; Sekar et al., 1990, 1993; Sukumar et
al., 1994). Crystal and molecular structure of 3-phenylpiperidin-4-one with 2,6-substitution of 4-chlorophenyl was reported,
which has similar structural feature of the present compound (Ompraba et al., 2003). In this present investigation, the X-ray
crystal and molecular structure of piperidin-4-one with 2,4,6-phenyl substitution is reported.
The configuration and conformation of the title compound, (I), and the atom numbering scheme are shown in the ORTEP
drawing (Fig. 1). The packing diagram of the title compound is show in Fig. 2. The piperidine ring adopts a chair conform-
ation, with the atoms C1, C2, C4 and C5 in a plane, whereas N1 and C3 deviate by -0.706 (3) and 0.494 (3) Å on either side
of this plane. The O1 atom is deviated much from the plane with 1.202 (4) Å. The phenyl rings are planar, with the r.m.s.
deviation of 0.0030 Å for ring P1 (C11···C16), 0.0038 Å for ring P2 (C21···C26) and 0.0052 Å for ring P3 (C31···C36). The
phenyl rings P1, P2 and P3 make dihedral angles with the piperidine plane, constituted by C1, C2, C4 and C5, of 86.9 (9),
81.9 (9) and 85.5 (8)°, respectively. According to the Cremer & Pople (1975) puckering analysis, the chair conformation
of the piperidine ring is confirmed by the amplitude-phase pair of 0.1542 (21) Å and 182.6 (8)° and the single puckering
coordinate of -0.5291 (22) Å. The equivalent spherical polar set is 0.5503 (22) Å, 163.9 (2)°, and 182.6 (8)°. The phenyl
rings P1, P2 and P3 are in equatorial 2,4,6-positions of the piperidine ring, making an angle with the puckering plane of
73.5 (1), 73.1 (1) and 67.2 (1)°, respectively. The O1 atom is also in equatorial position to the piperdine puckering plane
with an angle of 70.5 (1)°. The torsion angles H1—C1—C2—H2A of -173.4 (2)° and H4—C4—C5—H5 of 176.5 (2)°
show that the diaxial (anti) relationship of the former (6.6°) is deviated much than the later (3.5°) from the ideal value of
180°. The dihedral angles between phenyl rings P1 and P2, P2 and P3 & P3 and P1 are found to be 53.9 (9), 52.1 (8) and
7.6 (2)°, respectively. The C3 atom of the piperdine ring gives short contacts with the O1 atoms of different asymmetric
units as C3···O1 (-x + 1, + y - 1/2, -z + 1/2) (3.010 (3) Å) and C3···O1 (-x + 1, + y + 1/2, -z + 1/2) (3.171 (3) Å).
The crystal structure is stabilized through C—H···π and π–π interactions. Two intermolecular C—H···π interactions are
observed in the crystal structure with the distances of 4.111 (4) and 4.120 (3) Å to the centroids of the phenyl rings P2 and
P3 respectively (Table 1; Cg(2) is centroid of phenyl ring C21···C26 and Cg(3) is centroid of phenyl ring C31···C36). π–π
stacking interactions are observed as intra and intermolecular contacts. As an intramolecular π–π stacking, phenyls rings
P2 and P3 are stacked with the centroid to centroid separation of 4.504 (2) Å. Further, the phenyl rings P1 are stacked
almost parallel and involved in the π–π interactions around an inversion center (1 - x, 1 - y, -z) with a centroid to centroid
separation of 4.424 (2) Å.

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Experimental
Ammonium acetate (0.475 g, 0.0075 mol) was dissolved in ethanol (3 ml) by heating. Benzaldehyde (1.59 g, 0.015 mol) and
phenylacetone (1 g, 0.0075 mol) were added to this solution and the mixture heated until the color of the solution changed to
yellow. The solution was kept at room temperature for 2-3 days. The solid precipitated was filtered off, washed with ethanol
and recrystallized from ethanol and ethyl acetate. The pure compound was obtained in 61% yield.
Refinement
All C-bonded H atoms were fixed using geometrical constraints and their positions and thermal parameters were refined
isotropically riding on the carrier atom. Amine H atom (H1A) was found in a difference map and refined freely. All non-
hydrogen atoms are located and refined anisotropically.
Figures
Fig. 1. The molecular structure of title compound with atom numbering scheme and 50%
probability displacement ellipsoids (Sheldrick, 2008).
Fig. 2. Packing diagram of the molecule viewed down a axis (Sheldrick, 2008).
2,3,6-Triphenylpiperidin-4-one
Crystal data
C23H21NO
F000 = 696
Dx = 1.192 Mg m−3
Dm = 1.173 Mg m−3
Dm measured by Flotation technique using a liquid
mixture of CCl4 and xylene
Mo Kα radiation, λ = 0.71073 Å
Cell parameters from 25 reflections
θ = 9.7–14.4º
µ = 0.07 mm−1
T = 293 K
Needle, colourless
Mr = 327.41
Monoclinic, P21/c
Hall symbol: -P 2ybc
a = 12.144 (4) Å
b = 5.998 (2) Å
c = 25.127 (7) Å
β = 94.55 (2)º
V = 1824.3 (9) Å3
0.21 × 0.18 × 0.15 mm

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supplementary materials
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Z = 4
Data collection
Nonius MACH3 sealed tube
diffractometer
Radiation source: fine-focus sealed tube
Monochromator: graphite
T = 293 K
ω–2θ scans
Absorption correction: ψ scan
(North et al., 1968)
Tmin = 0.914, Tmax = 1.000
3552 measured reflections
3193 independent reflections
1906 reflections with I > 2σ(I)
Rint = 0.029
θmax = 25.0º
θmin = 2.3º
h = 0→14
k = −1→7
l = −29→29
3 standard reflections
every 60 min
intensity decay: <1%
Refinement
Refinement on F2
Hydrogen site location: inferred from neighbouring
sites
H atoms treated by a mixture of
independent and constrained refinement
w = 1/[σ2(Fo2) + (0.0616P)2 + 0.284P]
where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001
Δρmax = 0.16 e Å−3
Δρmin = −0.16 e Å−3
Extinction correction: SHELXTL (Bruker, 2000),
Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Least-squares matrix: full
R[F2 > 2σ(F2)] = 0.038
wR(F2) = 0.125
S = 1.02
3193 reflections
231 parameters
Primary atom site location: structure-invariant direct
methods
Secondary atom site location: difference Fourier map
Extinction coefficient: 0.0039 (12)
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
x
0.99723 (14)
0.9826
1.04235 (15)
1.0644
1.1077
0.96074 (15)
0.84239 (14)
0.8420
0.80792 (14)
0.8036
1.07919 (15)
y
0.4257 (3)
0.5792
0.2932 (3)
0.1463
0.3678
0.2677 (3)
0.2127 (3)
0.0553
0.3482 (3)
0.5062
0.4297 (4)
z
0.12658 (7)
0.1374
0.17569 (7)
0.1643
0.1917
0.21693 (7)
0.19584 (6)
0.1854
0.14452 (7)
0.1541
0.08460 (8)
Uiso*/Ueq
0.0525 (5)
0.063*
0.0553 (5)
0.066*
0.066*
0.0478 (4)
0.0463 (4)
0.056*
0.0476 (4)
0.057*
0.0586 (5)
C1
H1
C2
H2A
H2B
C3
C4
H4
C5
H5
C11