organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

3-Chloro-r-2,c-6-bis­­(4-fluoro­phen­yl)-3-methyl­piperidin-4-one

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aResearch and Development Centre, Bharathiar University, Coimbatore 641 046, Tamilnadu, India, bDepartment of Chemistry, Thiruvalluvar Arts and Science College, Kurinjipadi 607 302, Tamilnadu, India, cPostgraduate Research Department of Physics, Rajah Serfoji Government College (Autonomous), Thanjavur 613 005, Tamilnadu, India, dDepartment of Chemistry, Keene State College, 229 Main Street, Keene NH 03435-2001, USA, and eDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA
*Correspondence e-mail: jjasinski@keene.edu

Edited by R. J. Butcher, Howard University, USA (Received 18 September 2016; accepted 7 October 2016; online 11 October 2016)

The title compound, C18H16ClF2NO, contains one independent mol­ecule in the asymmetric unit, with the piperidin-4-one ring adopting a slightly distorted chair conformation and an equatorial orientation of all the substituents except chlorine. A single weak inter­molecular C—H⋯O inter­action influences the crystal packing, forming infinite one-dimensional zigzag chains along the a axis. The structure was refined as a two-component inversion twin.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Piperidones are an important group of heterocyclic compounds in the field of medicinal chemistry due to their biological activities, which include cytotoxic properties (Dimmock et al., 2001[Dimmock, J. R., Padmanilayam, M. P., Puthucode, R. N., Nazarali, A. J., Motaganahalli, N. L., Zello, G. A., Quail, J. W., Oloo, E. O., Kraatz, H. B., Prisciak, J. S., Allen, T. M., Santos, C. L., Balsarini, J., Clercq, E. D. & Manavathu, E. K. (2001). J. Med. Chem. 44, 586-593.]). They are also reported to possess analgesic, anti-inflammatory, central nervous system (CNS), local anaesthetic, anti­cancer, and anti­microbial activities (Perumal et al., 2001[Perumal, R. V., Agiraj, M. & Shanmugapandiyan, P. (2001). Indian Drugs, 38, 156-159.]). The synthesis and stereodynamics of piperidin-4-ones and their derivatives have been reported (Ponnuswamy et al., 2002[Ponnuswamy, S., Venkatraj, M., Jeyaraman, R., Suresh Kumar, M., Kumaran, D. & Ponnuswamy, M. N. (2002). Indian J. Chem. Sect. B, 41, 614-627.]). The present investigation was undertaken to establish the mol­ecular structure, the conformation of the heterocyclic ring and the orientation of the 4-fluoro­phenyl groups with respect to each other.

In the title compound, the piperidin-4-one ring is in a slightly distorted chair conformation [puckering parameters Q, θ, and φ = 0.548 (4) Å, 166.5 (4)°, and 182.7 (19)°, respectively] (Fig. 1[link]), with an equatorial orientation of all the substituents except chlorine. The dihedral angle between the mean planes of the two fluoro-substituted benzene rings is 49.3 (3)°. Bond lengths are in normal ranges (Allen et al., 1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). No classical hydrogen bonds are observed and all inter­molecular ππ inter­actions are greater than 4 Å. A single weak inter­molecular C5—H5⋯O1i inter­action influences the crystal packing, forming infinite one-dimensional zigzag chains along the a axis (Table 1[link] and Fig. 2[link]).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C5—H5⋯O1i 1.00 2.44 3.328 (5) 148
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z].
[Figure 1]
Figure 1
The mol­ecular structure, showing the atom-labeling scheme and 30% probability displacement ellipsoids.
[Figure 2]
Figure 2
The mol­ecular packing, viewed along the c axis. Dashed lines indicate weak inter­molecular C—H⋯O inter­actions. H atoms not involved in hydrogen bonding have been removed for clarity.

Synthesis and crystallization

A mixture of ammonium acetate (0.1 mol, 7.71 g), 4-fluoro­benzaldehyde (0.2 mol, 21.0 ml), and 3-chloro­butan-2-one (0.1 mol, 10.1 ml) in distilled ethanol was heated first to boiling. After cooling, the viscous liquid obtained was dissolved in ether (200 ml) and shaken with concentrated hydro­chloric acid (100 ml). The precipitated hydro­chloride of 3-chloro-r-2,c-6-bis­(4-fluoro­phen­yl)-3-methyl­piperidin-4-one was removed by filtration and washed first with a 40 ml mixture of ethanol and ether (1:1 v/v) and then with ether to remove most of the coloured impurities. The base was liberated from an ethanol solution by adding aqueous ammonia and then diluting with water. It was recrystallized from ethanol yielding colourless rod-like crystals (yield 3.5 g).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. The structure was refined as a two-component inversion twin (TWIN Law = −1 0 0 0 1 0 0 0 −1; BASF = 0.37605).

Table 2
Experimental details

Crystal data
Chemical formula C18H16ClF2NO
Mr 335.77
Crystal system, space group Orthorhombic, Pna21
Temperature (K) 173
a, b, c (Å) 6.2844 (2), 11.7141 (5), 21.6006 (10)
V3) 1590.15 (11)
Z 4
Radiation type Cu Kα
μ (mm−1) 2.35
Crystal size (mm) 0.48 × 0.15 × 0.14
 
Data collection
Diffractometer Rigaku Oxford Diffraction
Absorption correction Multi-scan (CrysAlis PRO; Rigaku OD, 2015[Rigaku OD (2015). CrysAlis PRO and CrysAlis RED. Rigaku Americas Corporation, The Woodlands, Texas, USA.])
Tmin, Tmax 0.441, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 10608, 2341, 2207
Rint 0.052
(sin θ/λ)max−1) 0.614
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.122, 1.08
No. of reflections 2341
No. of parameters 210
No. of restraints 1
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.56, −0.20
Absolute structure Flack x determined using 650 quotients [(I+)−(I)]/[(I+)+(I)] (Parsons et al., 2013[Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249-259.])
Absolute structure parameter 0.02 (3)
Computer programs: CrysAlis PRO (Rigaku OD, 2015[Rigaku OD (2015). CrysAlis PRO and CrysAlis RED. Rigaku Americas Corporation, The Woodlands, Texas, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]) and OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Structural data


Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2015); cell refinement: CrysAlis PRO (Rigaku OD, 2015); data reduction: CrysAlis PRO (Rigaku OD, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

3-Chloro-r-2,c-6-bis(4-fluorophenyl)-3-methylpiperidin-4-one top
Crystal data top
C18H16ClF2NODx = 1.403 Mg m3
Mr = 335.77Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, Pna21Cell parameters from 3685 reflections
a = 6.2844 (2) Åθ = 3.8–71.6°
b = 11.7141 (5) ŵ = 2.35 mm1
c = 21.6006 (10) ÅT = 173 K
V = 1590.15 (11) Å3Needle, colourless
Z = 40.48 × 0.15 × 0.14 mm
F(000) = 696
Data collection top
Rigaku Oxford Diffraction
diffractometer
2341 independent reflections
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source2207 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.052
Detector resolution: 16.0416 pixels mm-1θmax = 71.3°, θmin = 3.8°
ω scansh = 77
Absorption correction: multi-scan
(CrysAlis PRO; Rigaku OD, 2015)
k = 1414
Tmin = 0.441, Tmax = 1.000l = 2226
10608 measured reflections
Refinement top
Refinement on F2Hydrogen site location: mixed
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.049 w = 1/[σ2(Fo2) + (0.0862P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.122(Δ/σ)max < 0.001
S = 1.08Δρmax = 0.56 e Å3
2341 reflectionsΔρmin = 0.20 e Å3
210 parametersAbsolute structure: Flack x determined using 650 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
1 restraintAbsolute structure parameter: 0.02 (3)
Primary atom site location: structure-invariant direct methods
Special details top

Experimental. IR (KBr): 3325.34 (N-H), 3075.55, 3008.86 (υC-H), 1716.35 (υC=O), 1609.56, 1508.41 (υC=C), 767.12 (υC-Cl) cm-1. 1H NMR (500 MHz, CDCl3): δ 7.54 - 7.03 (m, Aromatic protons), 4.06 - 4.03 (dd, H(6) proton), 3.94 (s, H(2) proton ), 3.45 - 3.40 (dd, H(5e) proton), 2.53-2.49 (dd, H(5a) proton), 2.07 (s, NH proton), 1.42 (s, CH3 proton).

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 taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refined as a 2-component twin.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl10.08854 (13)0.40538 (7)0.52705 (7)0.0446 (3)
F10.9527 (6)0.3396 (4)0.23545 (15)0.0731 (10)
F20.6850 (5)0.3219 (3)0.76478 (13)0.0620 (8)
O10.0162 (5)0.6728 (2)0.46516 (17)0.0479 (8)
N10.5435 (5)0.4835 (3)0.49061 (14)0.0317 (6)
H10.67210.46200.49760.038*
C10.4464 (5)0.5400 (3)0.54363 (19)0.0321 (7)
H1A0.50310.61970.54510.038*
C20.2029 (5)0.5480 (3)0.5335 (2)0.0347 (8)
C30.1544 (6)0.6011 (3)0.4701 (2)0.0353 (8)
C40.2845 (7)0.5591 (4)0.4168 (2)0.0435 (9)
H4A0.26770.61230.38150.052*
H4B0.23100.48340.40370.052*
C50.5239 (6)0.5493 (3)0.43340 (19)0.0357 (8)
H50.58270.62750.44040.043*
C60.6454 (6)0.4932 (4)0.38161 (19)0.0377 (8)
C70.6428 (8)0.3745 (4)0.3746 (2)0.0445 (9)
H70.56860.32880.40380.053*
C80.7467 (9)0.3231 (4)0.3258 (2)0.0520 (10)
H80.74550.24240.32120.062*
C90.8523 (8)0.3909 (5)0.2838 (2)0.0517 (11)
C100.8613 (8)0.5067 (5)0.2891 (2)0.0541 (11)
H100.93690.55140.25970.065*
C110.7571 (8)0.5577 (4)0.3385 (2)0.0462 (9)
H110.76230.63830.34300.055*
C120.5098 (6)0.4818 (3)0.60302 (18)0.0324 (7)
C130.5488 (7)0.5447 (4)0.6568 (2)0.0397 (9)
H130.53560.62540.65570.048*
C140.6059 (7)0.4923 (4)0.7111 (2)0.0438 (9)
H140.63010.53570.74750.053*
C150.6271 (7)0.3753 (4)0.7115 (2)0.0447 (9)
C160.5943 (6)0.3102 (4)0.6598 (2)0.0405 (9)
H160.61260.22970.66120.049*
C170.5340 (6)0.3637 (3)0.60545 (19)0.0359 (8)
H170.50880.31940.56940.043*
C180.0902 (7)0.6093 (5)0.5858 (2)0.0495 (12)
H18A0.06000.61990.57500.074*
H18B0.15690.68390.59250.074*
H18C0.10070.56370.62370.074*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0329 (4)0.0338 (4)0.0673 (6)0.0052 (3)0.0073 (4)0.0127 (4)
F10.071 (2)0.104 (3)0.0439 (15)0.0193 (18)0.0142 (14)0.0073 (16)
F20.0677 (18)0.076 (2)0.0426 (14)0.0096 (14)0.0129 (13)0.0101 (14)
O10.0387 (14)0.0370 (14)0.068 (2)0.0091 (12)0.0078 (14)0.0069 (14)
N10.0281 (14)0.0305 (14)0.0364 (17)0.0024 (11)0.0015 (11)0.0010 (12)
C10.0264 (15)0.0243 (14)0.046 (2)0.0016 (11)0.0007 (14)0.0024 (14)
C20.0306 (16)0.0272 (13)0.046 (2)0.0017 (11)0.0021 (16)0.0038 (15)
C30.0302 (18)0.0279 (18)0.048 (2)0.0026 (13)0.0069 (16)0.0062 (15)
C40.043 (2)0.043 (2)0.044 (2)0.0059 (17)0.0089 (17)0.0057 (17)
C50.0354 (17)0.0298 (17)0.042 (2)0.0033 (14)0.0013 (16)0.0013 (15)
C60.0366 (18)0.0403 (19)0.036 (2)0.0017 (16)0.0024 (15)0.0034 (16)
C70.054 (2)0.0347 (19)0.045 (2)0.0015 (17)0.0019 (19)0.0008 (18)
C80.059 (3)0.051 (2)0.047 (2)0.008 (2)0.002 (2)0.002 (2)
C90.043 (2)0.074 (3)0.038 (2)0.007 (2)0.0007 (19)0.000 (2)
C100.049 (2)0.074 (3)0.040 (2)0.000 (2)0.0026 (18)0.015 (2)
C110.046 (2)0.046 (2)0.047 (2)0.0040 (17)0.0002 (19)0.0101 (18)
C120.0256 (15)0.0325 (16)0.0390 (18)0.0012 (13)0.0022 (13)0.0025 (15)
C130.039 (2)0.039 (2)0.042 (2)0.0005 (17)0.0014 (16)0.0049 (18)
C140.039 (2)0.055 (3)0.037 (2)0.0006 (17)0.0026 (16)0.0086 (19)
C150.0363 (19)0.057 (3)0.041 (2)0.0039 (18)0.0053 (17)0.0046 (19)
C160.037 (2)0.037 (2)0.048 (2)0.0057 (15)0.0024 (16)0.0034 (18)
C170.0340 (17)0.0339 (18)0.0397 (19)0.0027 (14)0.0010 (15)0.0049 (15)
C180.041 (2)0.057 (3)0.051 (3)0.0173 (18)0.0040 (19)0.003 (2)
Geometric parameters (Å, º) top
Cl1—C21.824 (3)C7—C81.379 (7)
F1—C91.360 (6)C8—H80.9500
F2—C151.360 (5)C8—C91.376 (7)
O1—C31.213 (5)C9—C101.363 (8)
N1—H10.8599C10—H100.9500
N1—C11.457 (5)C10—C111.388 (7)
N1—C51.461 (5)C11—H110.9500
C1—H1A1.0000C12—C131.397 (5)
C1—C21.548 (4)C12—C171.392 (5)
C1—C121.507 (5)C13—H130.9500
C2—C31.535 (6)C13—C141.372 (7)
C2—C181.515 (6)C14—H140.9500
C3—C41.495 (6)C14—C151.376 (7)
C4—H4A0.9900C15—C161.368 (6)
C4—H4B0.9900C16—H160.9500
C4—C51.551 (5)C16—C171.384 (6)
C5—H51.0000C17—H170.9500
C5—C61.505 (6)C18—H18A0.9800
C6—C71.399 (6)C18—H18B0.9800
C6—C111.389 (6)C18—H18C0.9800
C7—H70.9500
C1—N1—H1112.9C7—C8—H8120.6
C1—N1—C5112.9 (3)C9—C8—C7118.7 (4)
C5—N1—H1112.5C9—C8—H8120.6
N1—C1—H1A107.5F1—C9—C8118.4 (5)
N1—C1—C2109.3 (3)F1—C9—C10119.0 (5)
N1—C1—C12110.7 (3)C10—C9—C8122.7 (4)
C2—C1—H1A107.5C9—C10—H10120.9
C12—C1—H1A107.5C9—C10—C11118.2 (4)
C12—C1—C2114.1 (3)C11—C10—H10120.9
C1—C2—Cl1110.2 (2)C6—C11—C10121.3 (4)
C3—C2—Cl1103.0 (2)C6—C11—H11119.3
C3—C2—C1110.3 (3)C10—C11—H11119.3
C18—C2—Cl1107.9 (3)C13—C12—C1121.0 (3)
C18—C2—C1112.7 (3)C17—C12—C1120.7 (3)
C18—C2—C3112.4 (3)C17—C12—C13118.3 (4)
O1—C3—C2120.1 (4)C12—C13—H13119.3
O1—C3—C4123.4 (4)C14—C13—C12121.4 (4)
C4—C3—C2116.5 (3)C14—C13—H13119.3
C3—C4—H4A109.2C13—C14—H14120.8
C3—C4—H4B109.2C13—C14—C15118.4 (4)
C3—C4—C5112.1 (3)C15—C14—H14120.8
H4A—C4—H4B107.9F2—C15—C14119.3 (4)
C5—C4—H4A109.2F2—C15—C16118.3 (4)
C5—C4—H4B109.2C16—C15—C14122.4 (4)
N1—C5—C4108.5 (3)C15—C16—H16120.6
N1—C5—H5108.9C15—C16—C17118.7 (4)
N1—C5—C6110.8 (3)C17—C16—H16120.6
C4—C5—H5108.9C12—C17—H17119.6
C6—C5—C4110.7 (3)C16—C17—C12120.8 (4)
C6—C5—H5108.9C16—C17—H17119.6
C7—C6—C5120.5 (4)C2—C18—H18A109.5
C11—C6—C5121.1 (4)C2—C18—H18B109.5
C11—C6—C7118.3 (4)C2—C18—H18C109.5
C6—C7—H7119.6H18A—C18—H18B109.5
C8—C7—C6120.8 (4)H18A—C18—H18C109.5
C8—C7—H7119.6H18B—C18—H18C109.5
Cl1—C2—C3—O1106.0 (3)C4—C5—C6—C1198.1 (4)
Cl1—C2—C3—C473.7 (4)C5—N1—C1—C265.3 (3)
F1—C9—C10—C11179.7 (4)C5—N1—C1—C12168.2 (3)
F2—C15—C16—C17179.6 (4)C5—C6—C7—C8177.4 (4)
O1—C3—C4—C5136.3 (4)C5—C6—C11—C10177.0 (4)
N1—C1—C2—Cl161.3 (3)C6—C7—C8—C90.3 (7)
N1—C1—C2—C351.7 (3)C7—C6—C11—C101.0 (7)
N1—C1—C2—C18178.1 (3)C7—C8—C9—F1179.4 (4)
N1—C1—C12—C13142.7 (3)C7—C8—C9—C101.1 (8)
N1—C1—C12—C1736.4 (4)C8—C9—C10—C110.8 (7)
N1—C5—C6—C740.5 (5)C9—C10—C11—C60.3 (7)
N1—C5—C6—C11141.5 (4)C11—C6—C7—C80.7 (7)
C1—N1—C5—C464.1 (4)C12—C1—C2—Cl163.2 (4)
C1—N1—C5—C6174.3 (3)C12—C1—C2—C3176.2 (3)
C1—C2—C3—O1136.4 (4)C12—C1—C2—C1857.4 (4)
C1—C2—C3—C443.9 (4)C12—C13—C14—C150.9 (6)
C1—C12—C13—C14179.8 (4)C13—C12—C17—C160.3 (6)
C1—C12—C17—C16179.3 (3)C13—C14—C15—F2179.5 (4)
C2—C1—C12—C1393.6 (4)C13—C14—C15—C160.3 (7)
C2—C1—C12—C1787.4 (4)C14—C15—C16—C171.1 (7)
C2—C3—C4—C544.0 (4)C15—C16—C17—C120.8 (6)
C3—C4—C5—N151.1 (4)C17—C12—C13—C141.2 (6)
C3—C4—C5—C6172.9 (3)C18—C2—C3—O19.9 (5)
C4—C5—C6—C779.9 (5)C18—C2—C3—C4170.4 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C5—H5···O1i1.002.443.328 (5)148
Symmetry code: (i) x+1/2, y+3/2, z.
 

Acknowledgements

The authors would like to acknowledge the Sophisticated Analytical Instrument Facility (SAIF), IITM, Chennai, for recording the NMR spectra. We extend our thanks to the Principal Dr N. Seraman, Chairman Mr R. Sattanathan and Treasurer Mr T. Ramalingam of Thiruvalluvar Arts and Science College for giving permission to carry out research work in the Chemistry Laboratory. JPJ acknowledges the NSF–MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.

References

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