1-Dichloro­acetyl-t-3,t-5-dimethyl-r-2,c-6-diphenyl­piperidin-4-one

Sugumar, P.; Kayalvizhi, R.; Mini, R.; Ponnuswamy, S.; Ponnuswamy, M.N.

doi:10.1107/S1600536813007927

organic compounds

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ISSN: 2056-9890

Volume 69| Part 4| April 2013| Page o609

doi:10.1107/S1600536813007927

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1-Dichloroacetyl-t-3,t-5-dimethyl-r-2,c-6-diphenylpiperidin-4-one

P. Sugumar,^a R. Kayalvizhi,^b R. Mini,^b S. Ponnuswamy ^b and M. N. Ponnuswamy ^a ^*

^aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and ^bDepartment of Chemistry, Government Arts College (Autonomous), Coimbatore 641 018, India
^*Correspondence e-mail: mnpsy2004@yahoo.com

(Received 1 March 2013; accepted 21 March 2013; online 28 March 2013)

In the title compound, C₂₁H₂₁Cl₂NO₂, the piperidine ring adopts a distorted boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend angles of 87.9 (7) and 70.8 (9)°, respectively, with the best plane through the piperidine ring. In the crystal, molecules are connected by C—H⋯O and C—H⋯Cl interactions into layers in the ab plane.

Related literature

For the biological activity of piperidine derivatives, see: Aridoss et al. (2009 ); Michael (2001 ); Pinder (1992 ); Rubiralta et al. (1991 ). For puckering parameters, see: Cremer & Pople (1975 ). For asymmetry parameters, see: Nardelli (1983 ). For hydrogen-bond motifs, see: Bernstein et al.(1995 ).

Experimental

Crystal data

C₂₁H₂₁Cl₂NO₂
M_r = 390.29
Monoclinic, P 2₁
a = 8.278 (2) Å
b = 9.714 (3) Å
c = 11.847 (3) Å
β = 90.578 (9)°
V = 952.5 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.36 mm⁻¹
T = 293 K
0.20 × 0.18 × 0.17 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.931, T_max = 0.944
8874 measured reflections
4241 independent reflections
3962 reflections with I > 2σ(I)
R_int = 0.025

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.088
S = 1.03
4241 reflections
235 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.31 e Å⁻³
Absolute structure: Flack (1983 ), 1745 Friedel pairs
Flack parameter: 0.01 (5)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O1ⁱ	0.98	2.45	3.379 (2)	159
C20—H20⋯O1ⁱ	0.98	2.53	3.273 (2)	132
C21—H21C⋯Cl1ⁱⁱ	0.96	2.81	3.702 (2)	155
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, -z]$ ; (ii) $[-x+1, y+{\script{1\over 2}}, -z]$ .

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); 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 for Windows (Farrugia, 2012 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813007927/bt6893sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813007927/bt6893Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813007927/bt6893Isup3.cml

checkCIF report

Comment top

Piperidine derivatives are the valuable heterocyclic compounds in the field of medicinal chemistry. The compounds possessing an amide bond linkage have a wide range of biological activities such as antimicrobial, anti-inflammatory, antiviral, antimalarial and general anesthetics (Aridoss et al., 2009). Functionalized piperidines are familiar substructures found in biologically active natural products and synthetic pharmaceuticals (Michael, 2001; Pinder, 1992; Rubiralta et al., 1991). Against this background and to ascertain the molecular structure and conformation, the X-ray crystal structure determination of the title compound has been carried out.

The ORTEP plot of the molecule is shown in Fig. 1. The title compound crystallizes in the monoclinic space group P2₁. The piperidine ring adopts a distorted boat conformation. The puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) are: q₂=0.7556 (2) Å, q₃ = -0.010 (2) Å, ϕ₂ = 287.05 (1)° and Δ_s(C3 & C6)= 17.08 (1)°. The sum of the bond angles around N1 (359.1°) is in accordance with sp² hybridization.

The carbonyl group is oriented syn to C2 [C2—N1—C7—O1=] -6.5 (2)° and anti to C6 [C6—N1—C7—O1=] -176.7 (1)°. The best plane of the piperidine ring and the attached phenyl rings [C7—C12 and C13—C18] enclose dihedral angles of 87.9 (7)° and 70.8 (9)°. The two phenyl rings are oriented to each other with a dihedral angle of 54.01 (1)°.

The crystal packing reveals that the molecules are linked through a network of C—H···O and C—H···Cl intermolecular interactions. Atoms C2 and C20 of the molecule at (x, y, z) donate a proton to bifurcated acceptor atom O1 of the molecule at (1 - x,-1/2 + y,-z), which form two different C(5) and C(8) chains (Bernstein et al., 1995) forming layers in the ab plane as shown in Fig. 2.

Related literature top

For the biological activity of piperidine derivatives, see: Aridoss et al. (2009); Michael (2001); Pinder (1992); Rubiralta et al. (1991). For puckering parameters, see: Cremer & Pople (1975). For asymmetry parameters, see: Nardelli (1983). For hydrogen-bond motifs, see: Bernstein et al.(1995).

Experimental top

t-3,t-5-Dimethyl-r-2,c-6-diphenylpiperidin-4-one (5 mmol) was dissolved in 60 ml of anhydrous benzene. To this solution, dichloroacetylchloride (20 mmol) and triethylamine (20 mmol) were added and the reaction mixture was allowed to stirr for 8 h. The course of the reaction was monitored by TLC. The organic layer was dried over anhydrous Na₂SO₄ and the resulting pasty mass was purified by recrystallization from ethyl acetate. Yield: 70%, Melting point: 190–92°C

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing the atomic numbering and displacement ellipsoids drawn at 50% probability level.
	Fig. 2. The crystal packing of the molecules. H atoms not involved in hydrogen bonding (dashed lines) have been omitted for clarity.

1-Dichloroacetyl-t-3,t-5-dimethyl-r-2,c-6-diphenylpiperidin-4-one top

Crystal data top

C₂₁H₂₁Cl₂NO₂	F(000) = 408
M_r = 390.29	D_x = 1.361 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 3962 reflections
a = 8.278 (2) Å	θ = 1.7–28.4°
b = 9.714 (3) Å	µ = 0.36 mm⁻¹
c = 11.847 (3) Å	T = 293 K
β = 90.578 (9)°	Block, white crystalline
V = 952.5 (5) Å³	0.20 × 0.18 × 0.17 mm
Z = 2

Data collection top

Bruker SMART APEXII CCD diffractometer	4241 independent reflections
Radiation source: fine-focus sealed tube	3962 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
ω and ϕ scans	θ_max = 28.4°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −10→10
T_min = 0.931, T_max = 0.944	k = −11→12
8874 measured reflections	l = −15→15

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.032	H-atom parameters constrained
wR(F²) = 0.088	w = 1/[σ²(F_o²) + (0.0442P)² + 0.1557P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
4241 reflections	Δρ_max = 0.31 e Å⁻³
235 parameters	Δρ_min = −0.31 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 1745 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.01 (5)

Crystal data top

C₂₁H₂₁Cl₂NO₂	V = 952.5 (5) Å³
M_r = 390.29	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 8.278 (2) Å	µ = 0.36 mm⁻¹
b = 9.714 (3) Å	T = 293 K
c = 11.847 (3) Å	0.20 × 0.18 × 0.17 mm
β = 90.578 (9)°

Data collection top

Bruker SMART APEXII CCD diffractometer	4241 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	3962 reflections with I > 2σ(I)
T_min = 0.931, T_max = 0.944	R_int = 0.025
8874 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	H-atom parameters constrained
wR(F²) = 0.088	Δρ_max = 0.31 e Å⁻³
S = 1.03	Δρ_min = −0.31 e Å⁻³
4241 reflections	Absolute structure: Flack (1983), 1745 Friedel pairs
235 parameters	Absolute structure parameter: 0.01 (5)
1 restraint

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on 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) top

	x	y	z	U_iso*/U_eq
C2	0.41560 (17)	0.55485 (16)	0.18606 (12)	0.0275 (3)
H2	0.4759	0.5181	0.1220	0.033*
C3	0.42988 (17)	0.71381 (17)	0.18432 (12)	0.0298 (3)
H3	0.3622	0.7493	0.2452	0.036*
C4	0.35940 (19)	0.76681 (17)	0.07391 (12)	0.0321 (3)
C5	0.19801 (19)	0.7045 (2)	0.03920 (12)	0.0349 (3)
H5	0.1242	0.7795	0.0186	0.042*
C6	0.12278 (18)	0.62258 (17)	0.13576 (13)	0.0315 (3)
H6	0.0301	0.5735	0.1030	0.038*
C7	0.05790 (17)	0.70465 (19)	0.23542 (12)	0.0332 (3)
C8	0.0412 (2)	0.8464 (2)	0.23415 (16)	0.0434 (4)
H8	0.0746	0.8959	0.1714	0.052*
C9	−0.0246 (2)	0.9155 (2)	0.32501 (19)	0.0522 (5)
H9	−0.0357	1.0107	0.3226	0.063*
C10	−0.0736 (2)	0.8441 (3)	0.41870 (17)	0.0537 (5)
H10	−0.1167	0.8908	0.4800	0.064*
C11	−0.0585 (2)	0.7033 (3)	0.42115 (16)	0.0523 (5)
H11	−0.0920	0.6545	0.4843	0.063*
C12	0.0064 (2)	0.6335 (2)	0.33014 (15)	0.0425 (4)
H12	0.0155	0.5381	0.3326	0.051*
C13	0.49049 (18)	0.49813 (17)	0.29406 (13)	0.0328 (3)
C14	0.4205 (2)	0.5223 (2)	0.39840 (14)	0.0430 (4)
H14	0.3252	0.5726	0.4032	0.052*
C15	0.4943 (3)	0.4706 (3)	0.49568 (18)	0.0602 (6)
H15	0.4470	0.4852	0.5655	0.072*
C16	0.6365 (3)	0.3980 (3)	0.4893 (2)	0.0650 (7)
H16	0.6850	0.3642	0.5548	0.078*
C17	0.7073 (3)	0.3752 (3)	0.3867 (2)	0.0596 (6)
H17	0.8035	0.3259	0.3828	0.071*
C18	0.6351 (2)	0.4259 (2)	0.28862 (17)	0.0424 (4)
H18	0.6838	0.4115	0.2192	0.051*
C19	0.1845 (2)	0.38367 (19)	0.17034 (15)	0.0373 (3)
C20	0.3085 (2)	0.26688 (18)	0.17704 (14)	0.0373 (3)
H20	0.4172	0.3033	0.1639	0.045*
C21	0.6019 (2)	0.7649 (2)	0.20659 (16)	0.0467 (4)
H21A	0.6406	0.7286	0.2772	0.070*
H21B	0.6022	0.8637	0.2097	0.070*
H21C	0.6709	0.7346	0.1469	0.070*
C22	0.2237 (3)	0.6139 (2)	−0.06545 (14)	0.0496 (5)
H22A	0.1226	0.5737	−0.0883	0.074*
H22B	0.2995	0.5422	−0.0476	0.074*
H22C	0.2649	0.6693	−0.1258	0.074*
N1	0.24080 (15)	0.51501 (14)	0.17151 (10)	0.0289 (3)
O1	0.42761 (17)	0.84953 (16)	0.01538 (11)	0.0479 (3)
O2	0.04081 (17)	0.35524 (17)	0.16311 (17)	0.0645 (4)
Cl1	0.25867 (8)	0.14398 (5)	0.07228 (5)	0.06394 (16)
Cl2	0.30062 (9)	0.18963 (7)	0.31158 (5)	0.07162 (19)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C2	0.0262 (6)	0.0266 (8)	0.0297 (6)	−0.0013 (5)	−0.0018 (5)	0.0000 (5)
C3	0.0304 (7)	0.0279 (8)	0.0310 (6)	−0.0042 (6)	−0.0020 (5)	0.0007 (6)
C4	0.0377 (8)	0.0263 (8)	0.0324 (7)	0.0037 (6)	0.0017 (6)	0.0005 (6)
C5	0.0378 (7)	0.0354 (9)	0.0315 (7)	0.0045 (7)	−0.0055 (6)	0.0027 (6)
C6	0.0287 (7)	0.0307 (8)	0.0349 (7)	0.0009 (6)	−0.0062 (5)	−0.0001 (6)
C7	0.0242 (6)	0.0358 (8)	0.0395 (7)	0.0013 (6)	−0.0021 (5)	−0.0009 (7)
C8	0.0412 (8)	0.0362 (10)	0.0530 (10)	0.0021 (7)	0.0023 (7)	0.0015 (8)
C9	0.0440 (10)	0.0418 (12)	0.0707 (13)	0.0046 (8)	0.0006 (9)	−0.0132 (10)
C10	0.0371 (9)	0.0712 (15)	0.0527 (11)	0.0061 (9)	0.0005 (7)	−0.0208 (10)
C11	0.0452 (9)	0.0680 (14)	0.0440 (9)	0.0016 (10)	0.0077 (7)	−0.0004 (10)
C12	0.0377 (8)	0.0437 (10)	0.0461 (8)	0.0023 (7)	0.0044 (6)	0.0034 (8)
C13	0.0331 (7)	0.0290 (8)	0.0360 (7)	−0.0048 (6)	−0.0061 (6)	0.0041 (6)
C14	0.0417 (9)	0.0524 (12)	0.0348 (8)	−0.0064 (8)	−0.0040 (6)	0.0025 (8)
C15	0.0681 (13)	0.0767 (17)	0.0357 (8)	−0.0239 (12)	−0.0115 (8)	0.0103 (9)
C16	0.0658 (14)	0.0669 (16)	0.0615 (13)	−0.0179 (12)	−0.0338 (11)	0.0273 (12)
C17	0.0469 (10)	0.0527 (13)	0.0785 (15)	0.0011 (9)	−0.0264 (10)	0.0176 (11)
C18	0.0376 (8)	0.0378 (10)	0.0517 (9)	0.0007 (7)	−0.0084 (7)	0.0055 (8)
C19	0.0361 (8)	0.0298 (9)	0.0458 (8)	−0.0041 (6)	−0.0025 (6)	−0.0042 (7)
C20	0.0464 (9)	0.0239 (8)	0.0417 (8)	−0.0052 (7)	0.0032 (7)	0.0003 (6)
C21	0.0419 (9)	0.0450 (11)	0.0530 (10)	−0.0171 (8)	−0.0098 (7)	0.0057 (8)
C22	0.0630 (11)	0.0531 (14)	0.0325 (8)	−0.0012 (9)	−0.0049 (7)	−0.0057 (8)
N1	0.0272 (6)	0.0259 (7)	0.0335 (6)	−0.0021 (5)	−0.0038 (4)	−0.0011 (5)
O1	0.0553 (7)	0.0419 (8)	0.0468 (7)	−0.0025 (6)	0.0068 (6)	0.0151 (6)
O2	0.0394 (7)	0.0393 (9)	0.1147 (14)	−0.0121 (6)	−0.0077 (8)	−0.0083 (9)
Cl1	0.0835 (4)	0.0399 (3)	0.0688 (3)	−0.0167 (3)	0.0168 (3)	−0.0214 (2)
Cl2	0.0933 (4)	0.0638 (4)	0.0576 (3)	−0.0154 (3)	−0.0061 (3)	0.0249 (3)

Geometric parameters (Å, º) top

C2—N1	1.5060 (19)	C12—H12	0.9300
C2—C13	1.519 (2)	C13—C18	1.390 (2)
C2—C3	1.549 (2)	C13—C14	1.390 (2)
C2—H2	0.9800	C14—C15	1.393 (3)
C3—C4	1.517 (2)	C14—H14	0.9300
C3—C21	1.528 (2)	C15—C16	1.375 (4)
C3—H3	0.9800	C15—H15	0.9300
C4—O1	1.205 (2)	C16—C17	1.372 (4)
C4—C5	1.520 (2)	C16—H16	0.9300
C5—C6	1.531 (2)	C17—C18	1.392 (3)
C5—C22	1.537 (2)	C17—H17	0.9300
C5—H5	0.9800	C18—H18	0.9300
C6—N1	1.489 (2)	C19—O2	1.224 (2)
C6—C7	1.527 (2)	C19—N1	1.358 (2)
C6—H6	0.9800	C19—C20	1.531 (3)
C7—C8	1.384 (3)	C20—Cl2	1.7634 (18)
C7—C12	1.389 (2)	C20—Cl1	1.7679 (18)
C8—C9	1.385 (3)	C20—H20	0.9800
C8—H8	0.9300	C21—H21A	0.9600
C9—C10	1.373 (3)	C21—H21B	0.9600
C9—H9	0.9300	C21—H21C	0.9600
C10—C11	1.373 (4)	C22—H22A	0.9600
C10—H10	0.9300	C22—H22B	0.9600
C11—C12	1.387 (3)	C22—H22C	0.9600
C11—H11	0.9300

N1—C2—C13	112.74 (12)	C7—C12—H12	119.7
N1—C2—C3	109.15 (12)	C18—C13—C14	119.57 (15)
C13—C2—C3	110.01 (12)	C18—C13—C2	119.23 (14)
N1—C2—H2	108.3	C14—C13—C2	121.15 (15)
C13—C2—H2	108.3	C13—C14—C15	119.4 (2)
C3—C2—H2	108.3	C13—C14—H14	120.3
C4—C3—C21	112.84 (14)	C15—C14—H14	120.3
C4—C3—C2	108.73 (12)	C16—C15—C14	120.5 (2)
C21—C3—C2	113.12 (14)	C16—C15—H15	119.7
C4—C3—H3	107.3	C14—C15—H15	119.7
C21—C3—H3	107.3	C17—C16—C15	120.35 (18)
C2—C3—H3	107.3	C17—C16—H16	119.8
O1—C4—C3	122.95 (15)	C15—C16—H16	119.8
O1—C4—C5	121.70 (15)	C16—C17—C18	119.9 (2)
C3—C4—C5	115.32 (13)	C16—C17—H17	120.1
C4—C5—C6	111.58 (12)	C18—C17—H17	120.1
C4—C5—C22	108.55 (14)	C13—C18—C17	120.20 (19)
C6—C5—C22	111.46 (16)	C13—C18—H18	119.9
C4—C5—H5	108.4	C17—C18—H18	119.9
C6—C5—H5	108.4	O2—C19—N1	123.08 (17)
C22—C5—H5	108.4	O2—C19—C20	119.15 (17)
N1—C6—C7	112.41 (12)	N1—C19—C20	117.76 (14)
N1—C6—C5	107.86 (12)	C19—C20—Cl2	109.33 (12)
C7—C6—C5	117.09 (14)	C19—C20—Cl1	108.19 (12)
N1—C6—H6	106.3	Cl2—C20—Cl1	109.67 (10)
C7—C6—H6	106.3	C19—C20—H20	109.9
C5—C6—H6	106.3	Cl2—C20—H20	109.9
C8—C7—C12	118.20 (17)	Cl1—C20—H20	109.9
C8—C7—C6	123.16 (15)	C3—C21—H21A	109.5
C12—C7—C6	118.58 (17)	C3—C21—H21B	109.5
C7—C8—C9	120.92 (18)	H21A—C21—H21B	109.5
C7—C8—H8	119.5	C3—C21—H21C	109.5
C9—C8—H8	119.5	H21A—C21—H21C	109.5
C10—C9—C8	120.4 (2)	H21B—C21—H21C	109.5
C10—C9—H9	119.8	C5—C22—H22A	109.5
C8—C9—H9	119.8	C5—C22—H22B	109.5
C9—C10—C11	119.47 (19)	H22A—C22—H22B	109.5
C9—C10—H10	120.3	C5—C22—H22C	109.5
C11—C10—H10	120.3	H22A—C22—H22C	109.5
C10—C11—C12	120.4 (2)	H22B—C22—H22C	109.5
C10—C11—H11	119.8	C19—N1—C6	115.62 (13)
C12—C11—H11	119.8	C19—N1—C2	124.85 (13)
C11—C12—C7	120.6 (2)	C6—N1—C2	118.62 (12)
C11—C12—H12	119.7

N1—C2—C3—C4	−57.74 (15)	N1—C2—C13—C18	128.73 (16)
C13—C2—C3—C4	178.07 (11)	C3—C2—C13—C18	−109.19 (17)
N1—C2—C3—C21	176.08 (12)	N1—C2—C13—C14	−54.1 (2)
C13—C2—C3—C21	51.89 (17)	C3—C2—C13—C14	68.04 (19)
C21—C3—C4—O1	−5.9 (2)	C18—C13—C14—C15	−1.7 (3)
C2—C3—C4—O1	−132.20 (17)	C2—C13—C14—C15	−178.90 (18)
C21—C3—C4—C5	172.05 (15)	C13—C14—C15—C16	1.0 (3)
C2—C3—C4—C5	45.70 (17)	C14—C15—C16—C17	−0.2 (4)
O1—C4—C5—C6	−170.08 (16)	C15—C16—C17—C18	0.1 (4)
C3—C4—C5—C6	12.0 (2)	C14—C13—C18—C17	1.6 (3)
O1—C4—C5—C22	66.7 (2)	C2—C13—C18—C17	178.85 (18)
C3—C4—C5—C22	−111.23 (16)	C16—C17—C18—C13	−0.8 (3)
C4—C5—C6—N1	−56.95 (17)	O2—C19—C20—Cl2	−73.1 (2)
C22—C5—C6—N1	64.59 (16)	N1—C19—C20—Cl2	107.58 (16)
C4—C5—C6—C7	70.99 (17)	O2—C19—C20—Cl1	46.2 (2)
C22—C5—C6—C7	−167.47 (14)	N1—C19—C20—Cl1	−133.03 (14)
N1—C6—C7—C8	136.15 (16)	O2—C19—N1—C6	−14.3 (3)
C5—C6—C7—C8	10.4 (2)	C20—C19—N1—C6	164.98 (13)
N1—C6—C7—C12	−46.81 (19)	O2—C19—N1—C2	176.81 (17)
C5—C6—C7—C12	−172.51 (14)	C20—C19—N1—C2	−3.9 (2)
C12—C7—C8—C9	0.2 (3)	C7—C6—N1—C19	104.61 (16)
C6—C7—C8—C9	177.28 (16)	C5—C6—N1—C19	−124.81 (15)
C7—C8—C9—C10	0.4 (3)	C7—C6—N1—C2	−85.74 (16)
C8—C9—C10—C11	−0.7 (3)	C5—C6—N1—C2	44.84 (17)
C9—C10—C11—C12	0.3 (3)	C13—C2—N1—C19	−56.66 (19)
C10—C11—C12—C7	0.4 (3)	C3—C2—N1—C19	−179.22 (14)
C8—C7—C12—C11	−0.6 (3)	C13—C2—N1—C6	134.73 (14)
C6—C7—C12—C11	−177.81 (15)	C3—C2—N1—C6	12.16 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O1ⁱ	0.98	2.45	3.379 (2)	159
C20—H20···O1ⁱ	0.98	2.53	3.273 (2)	132
C21—H21C···Cl1ⁱⁱ	0.96	2.81	3.702 (2)	155

Symmetry codes: (i) −x+1, y−1/2, −z; (ii) −x+1, y+1/2, −z.

Experimental details

Crystal data
Chemical formula	C₂₁H₂₁Cl₂NO₂
M_r	390.29
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	293
a, b, c (Å)	8.278 (2), 9.714 (3), 11.847 (3)
β (°)	90.578 (9)
V (Å³)	952.5 (5)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.36
Crystal size (mm)	0.20 × 0.18 × 0.17

Data collection
Diffractometer	Bruker SMART APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.931, 0.944
No. of measured, independent and observed [I > 2σ(I)] reflections	8874, 4241, 3962
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.669

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.088, 1.03
No. of reflections	4241
No. of parameters	235
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.31, −0.31
Absolute structure	Flack (1983), 1745 Friedel pairs
Absolute structure parameter	0.01 (5)

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O1ⁱ	0.98	2.45	3.379 (2)	158.6
C20—H20···O1ⁱ	0.98	2.53	3.273 (2)	132.2
C21—H21C···Cl1ⁱⁱ	0.96	2.81	3.702 (2)	155.2

Symmetry codes: (i) −x+1, y−1/2, −z; (ii) −x+1, y+1/2, −z.

Acknowledgements

PS thanks the UGC, New Delhi, for financial support in the form of a Research Fellowship in Science for Meritorious Students. SP thanks UGC, New Delhi, for financial assistance in the form of a major research project.

References

Aridoss, G., Parthiban, P., Ramachandran, R., Prakash, M., Kabilan, S. & Jeong, Y. T. (2009). Eur. J. Med. Chem. 44, 577–592. Web of Science CrossRef PubMed CAS Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Michael, J. P. (2001). The Alkaloids. Chemistry and Biology, edited by G. A. Cordell, Vol. 55, pp. 91–258. New York: Academic Press. Google Scholar
Nardelli, M. (1983). Acta Cryst. C39, 1141–1142. CrossRef CAS Web of Science IUCr Journals Google Scholar
Pinder, A. R. (1992). Nat. Prod. Rep. 9, 491–504. CrossRef CAS Web of Science Google Scholar
Rubiralta, M., Giralt, E. & Diez, A. (1991). Piperidine: Structure, Preparation, Reactivity, and Synthetic Applications of Piperidine and its Derivatives, pp. 225–312. Amsterdam: Elsevier. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar