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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

Abstract top

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) 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 intermolecular C-H...[pi] contacts and [pi]-[pi] stacking interactions involving phenyl rings [centroid-centroid distance = 4.424 (2) Å].

Comment top

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 conformation, 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.

Related literature top

For the biological importance of piperidone and its derivatives, 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 top

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 top

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.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of title compound with atom numbering scheme and 50% probability displacement ellipsoids (Sheldrick, 2008).
[Figure 2] Fig. 2. Packing diagram of the molecule viewed down a axis (Sheldrick, 2008).
2,3,6-Triphenylpiperidin-4-one top
Crystal data top
C23H21NOF(000) = 696
Mr = 327.41Dx = 1.192 Mg m−3
Dm = 1.173 Mg m−3
Dm measured by Flotation technique using a liquid mixture of CCl4 and xylene
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 25 reflections
a = 12.144 (4) Åθ = 9.7–14.4°
b = 5.998 (2) ŵ = 0.07 mm−1
c = 25.127 (7) ÅT = 293 K
β = 94.55 (2)°Needle, colourless
V = 1824.3 (9) Å30.21 × 0.18 × 0.15 mm
Z = 4
Data collection top
Nonius MACH3 sealed tube
diffractometer		1906 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.029
graphiteθmax = 25.0°, θmin = 2.3°
ω–2θ scansh = 0→14
Absorption correction: ψ scan
(North et al., 1968)		k = −1→7
Tmin = 0.914, Tmax = 1.000l = −29→29
3552 measured reflections3 standard reflections every 60 min
3193 independent reflections intensity decay: <1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.038H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.125 w = 1/[σ2(Fo2) + (0.0616P)2 + 0.284P]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
3193 reflectionsΔρmax = 0.16 e Å−3
231 parametersΔρmin = −0.16 e Å−3
0 restraintsExtinction correction: SHELXTL (Bruker, 2000), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0039 (12)
Crystal data top
C23H21NOV = 1824.3 (9) Å3
Mr = 327.41Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.144 (4) ŵ = 0.07 mm−1
b = 5.998 (2) ÅT = 293 K
c = 25.127 (7) Å0.21 × 0.18 × 0.15 mm
β = 94.55 (2)°
Data collection top
Nonius MACH3 sealed tube
diffractometer		1906 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)		Rint = 0.029
Tmin = 0.914, Tmax = 1.000θmax = 25.0°
3552 measured reflections3 standard reflections every 60 min
3193 independent reflections intensity decay: <1%
Refinement top
R[F2 > 2σ(F2)] = 0.038H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.125Δρmax = 0.16 e Å−3
S = 1.01Δρmin = −0.16 e Å−3
3193 reflectionsAbsolute structure: ?
231 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.99723 (14)0.4257 (3)0.12658 (7)0.0525 (5)
H10.98260.57920.13740.063*
C21.04235 (15)0.2932 (3)0.17569 (7)0.0553 (5)
H2A1.06440.14630.16430.066*
H2B1.10770.36780.19170.066*
C30.96074 (15)0.2677 (3)0.21693 (7)0.0478 (4)
C40.84239 (14)0.2127 (3)0.19584 (6)0.0463 (4)
H40.84200.05530.18540.056*
C50.80792 (14)0.3482 (3)0.14452 (7)0.0476 (4)
H50.80360.50620.15410.057*
C111.07919 (15)0.4297 (4)0.08460 (8)0.0586 (5)
C121.0872 (2)0.2564 (5)0.04918 (9)0.0847 (8)
H121.03910.13610.05010.102*
C131.1653 (2)0.2586 (6)0.01234 (11)0.1065 (10)
H131.16910.1398−0.01120.128*
C141.2362 (2)0.4296 (8)0.00998 (12)0.1083 (12)
H141.28930.4287−0.01470.130*
C151.2294 (2)0.6038 (7)0.04409 (15)0.1093 (11)
H151.27750.72380.04230.131*
C161.15128 (19)0.6046 (5)0.08169 (11)0.0870 (8)
H161.14790.72450.10500.104*
C210.69698 (15)0.2758 (3)0.11922 (7)0.0488 (4)
C220.60549 (16)0.4111 (4)0.12051 (8)0.0644 (6)
H220.61260.54910.13730.077*
C230.50388 (18)0.3465 (5)0.09750 (9)0.0797 (7)
H230.44340.44060.09900.096*
C240.49144 (19)0.1451 (5)0.07247 (9)0.0784 (7)
H240.42290.10210.05670.094*
C250.5808 (2)0.0072 (4)0.07088 (8)0.0753 (7)
H250.5728−0.13050.05400.090*
C260.68306 (17)0.0707 (4)0.09422 (8)0.0633 (5)
H260.7430−0.02520.09310.076*
C310.75856 (15)0.2369 (3)0.23659 (6)0.0476 (4)
C320.74957 (16)0.4355 (3)0.26422 (7)0.0568 (5)
H320.79730.55240.25820.068*
C330.67150 (18)0.4629 (4)0.30033 (8)0.0688 (6)
H330.66740.59670.31880.083*
C340.59921 (19)0.2924 (4)0.30919 (9)0.0733 (6)
H340.54630.31050.33360.088*
C350.60573 (18)0.0963 (4)0.28186 (9)0.0712 (6)
H350.5564−0.01840.28740.085*
C360.68516 (16)0.0677 (3)0.24617 (8)0.0597 (5)
H360.6895−0.06730.22830.072*
N10.89297 (12)0.3218 (3)0.10684 (6)0.0526 (4)
O10.98843 (11)0.2814 (2)0.26421 (5)0.0572 (4)
H1A0.8700 (15)0.387 (3)0.0769 (8)0.060 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0498 (10)0.0549 (11)0.0530 (10)0.0037 (9)0.0045 (8)0.0043 (9)
C20.0490 (10)0.0621 (12)0.0542 (11)0.0037 (9)−0.0003 (8)0.0023 (9)
C30.0580 (11)0.0383 (10)0.0463 (10)0.0045 (8)−0.0016 (8)0.0025 (8)
C40.0552 (10)0.0401 (9)0.0434 (9)0.0022 (8)0.0021 (8)−0.0001 (8)
C50.0518 (10)0.0470 (10)0.0441 (9)0.0053 (8)0.0045 (8)0.0022 (8)
C110.0501 (11)0.0716 (13)0.0540 (11)0.0066 (10)0.0041 (9)0.0158 (11)
C120.0804 (16)0.104 (2)0.0731 (15)0.0042 (14)0.0276 (13)−0.0026 (15)
C130.0892 (19)0.154 (3)0.0812 (18)0.021 (2)0.0349 (15)0.0061 (19)
C140.0672 (17)0.182 (4)0.0797 (19)0.038 (2)0.0269 (14)0.056 (2)
C150.0640 (16)0.134 (3)0.133 (3)−0.0043 (18)0.0240 (17)0.058 (2)
C160.0665 (14)0.0945 (19)0.1012 (19)−0.0062 (14)0.0146 (13)0.0186 (15)
C210.0511 (10)0.0572 (12)0.0383 (8)0.0038 (9)0.0053 (7)0.0033 (9)
C220.0568 (12)0.0752 (14)0.0607 (12)0.0116 (11)0.0016 (10)−0.0041 (11)
C230.0560 (13)0.108 (2)0.0742 (15)0.0164 (13)−0.0024 (11)−0.0066 (15)
C240.0578 (13)0.113 (2)0.0629 (14)−0.0084 (14)−0.0055 (10)0.0027 (14)
C250.0841 (16)0.0814 (16)0.0583 (13)−0.0117 (14)−0.0066 (11)−0.0106 (12)
C260.0657 (13)0.0689 (14)0.0544 (11)0.0067 (11)−0.0008 (10)−0.0082 (11)
C310.0548 (10)0.0473 (11)0.0402 (9)0.0003 (9)−0.0001 (8)0.0031 (8)
C320.0630 (12)0.0533 (12)0.0546 (10)−0.0052 (10)0.0089 (9)−0.0037 (9)
C330.0781 (14)0.0658 (14)0.0642 (13)0.0040 (12)0.0161 (11)−0.0094 (11)
C340.0736 (14)0.0881 (18)0.0611 (13)0.0026 (13)0.0224 (11)0.0009 (13)
C350.0710 (13)0.0754 (16)0.0694 (13)−0.0147 (12)0.0183 (11)0.0075 (12)
C360.0700 (12)0.0523 (12)0.0571 (11)−0.0078 (10)0.0061 (10)0.0001 (10)
N10.0505 (9)0.0654 (11)0.0419 (8)0.0059 (8)0.0034 (7)0.0056 (8)
O10.0705 (8)0.0531 (8)0.0463 (7)−0.0034 (6)−0.0062 (6)0.0019 (6)
Geometric parameters (Å, °) top
C1—N11.462 (2)C16—H160.9300
C1—C111.507 (3)C21—C221.378 (3)
C1—C21.532 (3)C21—C261.385 (3)
C1—H10.9800C22—C231.376 (3)
C2—C31.498 (2)C22—H220.9300
C2—H2A0.9700C23—C241.365 (4)
C2—H2B0.9700C23—H230.9300
C3—O11.212 (2)C24—C251.367 (3)
C3—C41.528 (3)C24—H240.9300
C4—C311.507 (2)C25—C261.384 (3)
C4—C51.553 (2)C25—H250.9300
C4—H40.9800C26—H260.9300
C5—N11.464 (2)C31—C361.384 (3)
C5—C211.507 (3)C31—C321.387 (3)
C5—H50.9800C32—C331.373 (3)
C11—C161.372 (3)C32—H320.9300
C11—C121.377 (3)C33—C341.377 (3)
C12—C131.377 (3)C33—H330.9300
C12—H120.9300C34—C351.367 (3)
C13—C141.344 (5)C34—H340.9300
C13—H130.9300C35—C361.379 (3)
C14—C151.358 (5)C35—H350.9300
C14—H140.9300C36—H360.9300
C15—C161.391 (4)N1—H1A0.87 (2)
C15—H150.9300
N1—C1—C11111.81 (15)C11—C16—C15120.4 (3)
N1—C1—C2107.26 (15)C11—C16—H16119.8
C11—C1—C2110.99 (15)C15—C16—H16119.8
N1—C1—H1108.9C22—C21—C26117.63 (18)
C11—C1—H1108.9C22—C21—C5121.05 (18)
C2—C1—H1108.9C26—C21—C5121.32 (17)
C3—C2—C1113.35 (15)C23—C22—C21121.5 (2)
C3—C2—H2A108.9C23—C22—H22119.3
C1—C2—H2A108.9C21—C22—H22119.3
C3—C2—H2B108.9C24—C23—C22120.4 (2)
C1—C2—H2B108.9C24—C23—H23119.8
H2A—C2—H2B107.7C22—C23—H23119.8
O1—C3—C2121.62 (17)C23—C24—C25119.3 (2)
O1—C3—C4122.35 (16)C23—C24—H24120.3
C2—C3—C4115.98 (14)C25—C24—H24120.3
C31—C4—C3114.28 (14)C24—C25—C26120.6 (2)
C31—C4—C5111.20 (14)C24—C25—H25119.7
C3—C4—C5111.06 (14)C26—C25—H25119.7
C31—C4—H4106.6C25—C26—C21120.6 (2)
C3—C4—H4106.6C25—C26—H26119.7
C5—C4—H4106.6C21—C26—H26119.7
N1—C5—C21110.42 (14)C36—C31—C32117.72 (17)
N1—C5—C4108.82 (14)C36—C31—C4121.78 (17)
C21—C5—C4111.87 (15)C32—C31—C4120.45 (16)
N1—C5—H5108.6C33—C32—C31121.28 (19)
C21—C5—H5108.6C33—C32—H32119.4
C4—C5—H5108.6C31—C32—H32119.4
C16—C11—C12117.7 (2)C32—C33—C34120.0 (2)
C16—C11—C1120.6 (2)C32—C33—H33120.0
C12—C11—C1121.7 (2)C34—C33—H33120.0
C11—C12—C13121.0 (3)C35—C34—C33119.64 (19)
C11—C12—H12119.5C35—C34—H34120.2
C13—C12—H12119.5C33—C34—H34120.2
C14—C13—C12121.0 (3)C34—C35—C36120.3 (2)
C14—C13—H13119.5C34—C35—H35119.8
C12—C13—H13119.5C36—C35—H35119.8
C13—C14—C15119.2 (3)C35—C36—C31121.0 (2)
C13—C14—H14120.4C35—C36—H36119.5
C15—C14—H14120.4C31—C36—H36119.5
C14—C15—C16120.7 (3)C1—N1—C5111.76 (14)
C14—C15—H15119.7C1—N1—H1A108.1 (13)
C16—C15—H15119.7C5—N1—H1A108.4 (13)
N1—C1—C2—C3−52.9 (2)N1—C5—C21—C2651.0 (2)
C11—C1—C2—C3−175.28 (16)C4—C5—C21—C26−70.4 (2)
C1—C2—C3—O1−140.17 (18)C26—C21—C22—C23−0.5 (3)
C1—C2—C3—C442.6 (2)C5—C21—C22—C23179.96 (18)
O1—C3—C4—C3115.3 (2)C21—C22—C23—C24−0.2 (3)
C2—C3—C4—C31−167.50 (15)C22—C23—C24—C250.6 (3)
O1—C3—C4—C5142.07 (17)C23—C24—C25—C26−0.2 (3)
C2—C3—C4—C5−40.7 (2)C24—C25—C26—C21−0.5 (3)
C31—C4—C5—N1179.04 (14)C22—C21—C26—C250.9 (3)
C3—C4—C5—N150.59 (19)C5—C21—C26—C25−179.60 (18)
C31—C4—C5—C21−58.7 (2)C3—C4—C31—C36−128.49 (18)
C3—C4—C5—C21172.87 (14)C5—C4—C31—C36104.8 (2)
N1—C1—C11—C16145.40 (19)C3—C4—C31—C3254.4 (2)
C2—C1—C11—C16−94.9 (2)C5—C4—C31—C32−72.3 (2)
N1—C1—C11—C12−36.8 (3)C36—C31—C32—C330.8 (3)
C2—C1—C11—C1282.9 (2)C4—C31—C32—C33178.04 (18)
C16—C11—C12—C130.3 (4)C31—C32—C33—C34−0.9 (3)
C1—C11—C12—C13−177.5 (2)C32—C33—C34—C350.0 (3)
C11—C12—C13—C140.2 (4)C33—C34—C35—C360.9 (3)
C12—C13—C14—C15−0.8 (4)C34—C35—C36—C31−1.0 (3)
C13—C14—C15—C161.0 (4)C32—C31—C36—C350.2 (3)
C12—C11—C16—C15−0.2 (3)C4—C31—C36—C35−177.06 (17)
C1—C11—C16—C15177.7 (2)C11—C1—N1—C5−171.28 (16)
C14—C15—C16—C11−0.5 (4)C2—C1—N1—C566.8 (2)
N1—C5—C21—C22−129.47 (18)C21—C5—N1—C1170.12 (15)
C4—C5—C21—C22109.2 (2)C4—C5—N1—C1−66.7 (2)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C14—H14···Cg2i0.933.374.111 (4)139
C35—H35···Cg3ii0.933.374.120 (3)138
Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x, y−1/2, −z+1/2.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C14—H14···Cg2i0.933.374.111 (4)139
C35—H35···Cg3ii0.933.374.120 (3)138
Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x, y−1/2, −z+1/2.
Acknowledgements top

NML, RA and SA sincerely thank the Vice-Chancellor and Management of the Kalasalingam University, Anand Nagar and Krishnan Koil, for their support and encouragement.

references
References top

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