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

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ISSN: 2056-9890
Volume 70| Part 9| September 2014| Pages o981-o982

Crystal structure of cis-1-(2-methyl-1,2,3,4-tetra­hydro­quinolin-4-yl)azepan-2-one

aDepartment of Chemistry, Kuvempu University, Jnanasahyadri, Shankaraghatta 577 451, India, bInstitution of Excellence, University of Mysore, Manasagangotri, Mysore 570 006, India, cDepartment of Chemistry, Yuvaraja's College, University of Mysore, Mysore 570 005, India, and dDepartment of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006, India
*Correspondence e-mail: lokanath@physics.uni-mysore.ac.in

Edited by D.-J. Xu, Zhejiang University (Yuquan Campus), China (Received 24 July 2014; accepted 2 August 2014; online 9 August 2014)

In the title compound, C16H22N2O, the azepan-2-one ring adopts a chair conformation, while the 1,2,3,4-tetra­hydro­pyridine ring adopts a half-chair conformation. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming supra­molecular chains propagated along [10-1], with weak C—H⋯O inter­actions occurring between the chains.

1. Related literature

For applications of tetra­hydro­quinolines, see: Konishi et al. (1990[Konishi, M., Ohkuma, H., Tsuno, T. & Oki, T. (1990). J. Am. Chem. Soc. 112, 3715-3716.]).

[Scheme 1]

2. Experimental

2.1. Crystal data

  • C16H22N2O

  • Mr = 258.36

  • Monoclinic, P 21 /n

  • a = 9.1640 (17) Å

  • b = 13.1687 (18) Å

  • c = 11.988 (2) Å

  • β = 96.825 (11)°

  • V = 1436.4 (4) Å3

  • Z = 4

  • Cu Kα radiation

  • μ = 0.59 mm−1

  • T = 296 K

  • 0.23 × 0.22 × 0.21 mm

2.2. Data collection

  • Bruker X8 Proteum diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.874, Tmax = 0.884

  • 7903 measured reflections

  • 2343 independent reflections

  • 2106 reflections with I > 2σ(I)

  • Rint = 0.028

2.3. Refinement

  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.139

  • S = 1.06

  • 2343 reflections

  • 173 parameters

  • H-atom parameters constrained

  • Δρmax = 0.34 e Å−3

  • Δρmin = −0.36 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O19i 0.86 2.40 2.988 (2) 126
C14—H14A⋯O19ii 0.97 2.57 3.320 (2) 134
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: Mercury.

Supporting information


Comment top

Tetrahydroquinolines are an important family of heterocyclic compounds having wide range of biological activities which includes antimalarial, antitumoral, antioxidant, etc. In particular 2-Methyl-1,2,3,4-tetrahydroquinoline is present in human brain and a natural antitumor antibiotic, has a complex structure built on the tetrahydroquinoline system (Konishi et al., 1990). Hence, in continuation of our effort to identify new quinoline based therapeutic agents, the title compound has been synthesized and herein we report its crystal structure.

The ORTEP of the molecule is shown in figure 1. The title compound is chiral. In the arbitrarily chosen asymmetric molecule, C2 has S configuration whereas C4 has R configuration. The azepan ring lies in the equatorial plane of the fused rings as indicated by the dihedral angle value of 66.28 (8)°. A study of torsion angles, asymmetric parameters and least squares plane calculations reveals that the quinoline ring in the structure adopts a half chair conformation with the atom C3 deviating by 0.3278 (18) Å from the least-squares plane defined by the atoms N1/C2/C3/C4/C5/C10. This is confirmed by the puckering amplitude Q = 0.4857 (18) Å. The structure exhibits weak intermolecular hydrogen bonds of the type C—H···O and N—H···O. The packing of the molecules when viewed along the a axis indicate that they are stacked in pairs.

Related literature top

For applications of tetrahydroquinolines, see: Konishi et al. (1990).

Experimental top

A catalytic amount of SbF3 (10 mol %) was added to the mixture of aniline(1 equivalent) and N-vinyl caprolactam(2–3 equivalent) in acetonitrile (5–10 ml). The reaction mixture was stirred at ambient temperature (~25 °C) for 20–70 min. The reaction was monitored by TLC by using ethyl acetate/hexane as eluent. After the completion of the reaction, the solvent was removed under vacuo. The crude product was then quenched with water and the catalyst was decomposed by addition of appropriate amount of sodium bicarbonate solution, extracted with ethyl acetate (10 ml × 5 times), dried and was purified by column chromatography using ethyl acetate/hexane as eluent (pet ether/ethyl acetate 80:20 v/v). The white solid crystals were obtained by slow evaporation method by using petroleum ether: ethyl acetate, 8:2 v/v as solvents. M.P. = 155–160 °C. Yield: 93%.

Refinement top

The hydrogen atoms were placed geometrically with N—H = 0.86, C—H = 0.93–0.98 Å, and allowed to ride on their parent atoms with Uiso(H) = 1.5Ueq(C) for the methyl H atoms and 1.2Ueq(N,C) for the others.

Computing details top

Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: Mercury (Macrae et al., 2008).

Figures top
[Figure 1] Fig. 1. A view of the title molecule, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A viewed along the a axis of the crystal packing of the title compound.
1-(2-Methyl-1,2,3,4-tetrahydroquinolin-4-yl)azepan-2-one top
Crystal data top
C16H22N2OF(000) = 560
Mr = 258.36Dx = 1.195 Mg m3
Monoclinic, P21/nCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ynCell parameters from 2343 reflections
a = 9.1640 (17) Åθ = 6.7–64.8°
b = 13.1687 (18) ŵ = 0.59 mm1
c = 11.988 (2) ÅT = 296 K
β = 96.825 (11)°Block, colorless
V = 1436.4 (4) Å30.23 × 0.22 × 0.21 mm
Z = 4
Data collection top
Bruker X8 Proteum
diffractometer
2343 independent reflections
Radiation source: Bruker MicroStar microfocus rotating anode2106 reflections with I > 2σ(I)
Helios multilayer optics monochromatorRint = 0.028
Detector resolution: 18.4 pixels mm-1θmax = 64.8°, θmin = 6.7°
ϕ and ω scansh = 1010
Absorption correction: multi-scan
(SADABS; Bruker, 2013)
k = 154
Tmin = 0.874, Tmax = 0.884l = 1413
7903 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.139H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0671P)2 + 0.4283P]
where P = (Fo2 + 2Fc2)/3
2343 reflections(Δ/σ)max < 0.001
173 parametersΔρmax = 0.34 e Å3
0 restraintsΔρmin = 0.36 e Å3
Crystal data top
C16H22N2OV = 1436.4 (4) Å3
Mr = 258.36Z = 4
Monoclinic, P21/nCu Kα radiation
a = 9.1640 (17) ŵ = 0.59 mm1
b = 13.1687 (18) ÅT = 296 K
c = 11.988 (2) Å0.23 × 0.22 × 0.21 mm
β = 96.825 (11)°
Data collection top
Bruker X8 Proteum
diffractometer
2343 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2013)
2106 reflections with I > 2σ(I)
Tmin = 0.874, Tmax = 0.884Rint = 0.028
7903 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.139H-atom parameters constrained
S = 1.06Δρmax = 0.34 e Å3
2343 reflectionsΔρmin = 0.36 e Å3
173 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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
xyzUiso*/Ueq
O190.20029 (15)0.75502 (10)0.32245 (11)0.0661 (5)
N10.53573 (16)0.85016 (11)0.01036 (12)0.0538 (5)
N120.28345 (14)0.90157 (10)0.25474 (10)0.0438 (4)
C20.60480 (18)0.82217 (14)0.10008 (15)0.0511 (6)
C30.52791 (17)0.87701 (14)0.18769 (14)0.0497 (5)
C40.36664 (17)0.84597 (12)0.17675 (13)0.0421 (5)
C50.29631 (17)0.85491 (12)0.05626 (13)0.0439 (5)
C60.1450 (2)0.86076 (16)0.03030 (16)0.0593 (6)
C70.0790 (2)0.86425 (19)0.07861 (17)0.0718 (8)
C80.1649 (3)0.86264 (17)0.16454 (16)0.0700 (7)
C90.3153 (2)0.85678 (14)0.14226 (15)0.0605 (7)
C100.38380 (19)0.85289 (12)0.03180 (14)0.0459 (5)
C110.7676 (2)0.84612 (19)0.1097 (2)0.0743 (8)
C130.28372 (19)1.01269 (13)0.25122 (14)0.0514 (6)
C140.3621 (2)1.06237 (15)0.35552 (17)0.0640 (7)
C150.2718 (3)1.06735 (17)0.45383 (18)0.0770 (8)
C160.2169 (3)0.96542 (17)0.49058 (17)0.0720 (8)
C170.1190 (2)0.90829 (16)0.40028 (17)0.0627 (7)
C180.20364 (18)0.84820 (14)0.32180 (13)0.0486 (6)
H10.588800.865100.062600.0640*
H20.592900.748900.109900.0610*
H3A0.535500.949800.177500.0600*
H3B0.574900.860100.262200.0600*
H40.363800.774000.197100.0510*
H60.086400.862400.088500.0710*
H70.022800.867700.093800.0860*
H80.121200.865500.238600.0840*
H90.372200.855400.201500.0730*
H11A0.811600.809200.053300.1120*
H11B0.813300.826700.182800.1120*
H11C0.780800.917600.099200.1120*
H13A0.182801.036400.240600.0620*
H13B0.330201.034400.186700.0620*
H14A0.389601.130800.336700.0770*
H14B0.451901.025000.378700.0770*
H15A0.331101.098300.517200.0920*
H15B0.187701.111200.433400.0920*
H16A0.162700.976100.554300.0860*
H16B0.301200.923200.515800.0860*
H17A0.056400.862300.436200.0750*
H17B0.056000.956600.356500.0750*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O190.0806 (9)0.0577 (9)0.0692 (9)0.0120 (7)0.0477 (7)0.0006 (6)
N10.0525 (8)0.0624 (9)0.0526 (8)0.0030 (7)0.0321 (7)0.0032 (7)
N120.0447 (7)0.0501 (8)0.0406 (7)0.0023 (6)0.0221 (6)0.0023 (6)
C20.0446 (9)0.0534 (10)0.0599 (10)0.0014 (7)0.0254 (8)0.0009 (8)
C30.0411 (8)0.0607 (10)0.0501 (9)0.0022 (7)0.0173 (7)0.0045 (8)
C40.0419 (8)0.0472 (9)0.0412 (8)0.0003 (7)0.0212 (6)0.0003 (7)
C50.0441 (9)0.0469 (9)0.0436 (9)0.0039 (7)0.0179 (7)0.0008 (7)
C60.0468 (10)0.0805 (13)0.0529 (10)0.0060 (9)0.0161 (8)0.0002 (9)
C70.0567 (11)0.0964 (16)0.0609 (12)0.0073 (11)0.0017 (9)0.0001 (11)
C80.0819 (14)0.0791 (14)0.0470 (10)0.0082 (11)0.0000 (10)0.0047 (9)
C90.0812 (14)0.0618 (11)0.0424 (9)0.0068 (9)0.0238 (9)0.0057 (8)
C100.0555 (9)0.0415 (9)0.0448 (9)0.0023 (7)0.0227 (7)0.0012 (7)
C110.0451 (10)0.0932 (16)0.0900 (15)0.0016 (10)0.0301 (10)0.0044 (12)
C130.0576 (10)0.0523 (10)0.0480 (9)0.0097 (8)0.0219 (8)0.0091 (7)
C140.0803 (13)0.0496 (11)0.0641 (12)0.0029 (9)0.0170 (10)0.0019 (9)
C150.1127 (18)0.0636 (13)0.0579 (12)0.0138 (12)0.0233 (12)0.0091 (10)
C160.0985 (16)0.0738 (14)0.0498 (11)0.0185 (12)0.0348 (10)0.0001 (9)
C170.0607 (11)0.0735 (13)0.0616 (11)0.0111 (9)0.0388 (9)0.0080 (10)
C180.0454 (9)0.0591 (11)0.0454 (9)0.0002 (7)0.0225 (7)0.0031 (7)
Geometric parameters (Å, º) top
O19—C181.228 (2)C2—H20.9800
N1—C21.446 (2)C3—H3A0.9700
N1—C101.386 (2)C3—H3B0.9700
N12—C41.470 (2)C4—H40.9800
N12—C131.464 (2)C6—H60.9300
N12—C181.347 (2)C7—H70.9300
N1—H10.8600C8—H80.9300
C2—C111.516 (3)C9—H90.9300
C2—C31.516 (2)C11—H11A0.9600
C3—C41.524 (2)C11—H11B0.9600
C4—C51.515 (2)C11—H11C0.9600
C5—C61.387 (2)C13—H13A0.9700
C5—C101.400 (2)C13—H13B0.9700
C6—C71.373 (3)C14—H14A0.9700
C7—C81.369 (3)C14—H14B0.9700
C8—C91.375 (3)C15—H15A0.9700
C9—C101.397 (2)C15—H15B0.9700
C13—C141.515 (3)C16—H16A0.9700
C14—C151.520 (3)C16—H16B0.9700
C15—C161.517 (3)C17—H17A0.9700
C16—C171.521 (3)C17—H17B0.9700
C17—C181.512 (3)
C2—N1—C10119.82 (14)C5—C4—H4107.00
C4—N12—C13118.48 (12)C5—C6—H6119.00
C4—N12—C18118.62 (13)C7—C6—H6119.00
C13—N12—C18122.79 (14)C6—C7—H7120.00
C2—N1—H1120.00C8—C7—H7120.00
C10—N1—H1120.00C7—C8—H8120.00
C3—C2—C11112.49 (16)C9—C8—H8120.00
N1—C2—C3108.91 (14)C8—C9—H9120.00
N1—C2—C11109.66 (16)C10—C9—H9120.00
C2—C3—C4109.79 (14)C2—C11—H11A109.00
N12—C4—C5111.95 (13)C2—C11—H11B109.00
C3—C4—C5111.08 (13)C2—C11—H11C109.00
N12—C4—C3112.50 (13)H11A—C11—H11B110.00
C6—C5—C10118.62 (15)H11A—C11—H11C110.00
C4—C5—C6121.27 (15)H11B—C11—H11C109.00
C4—C5—C10120.05 (14)N12—C13—H13A109.00
C5—C6—C7122.08 (17)N12—C13—H13B109.00
C6—C7—C8119.17 (19)C14—C13—H13A109.00
C7—C8—C9120.51 (18)C14—C13—H13B109.00
C8—C9—C10120.89 (17)H13A—C13—H13B108.00
N1—C10—C5120.90 (15)C13—C14—H14A109.00
N1—C10—C9120.33 (16)C13—C14—H14B109.00
C5—C10—C9118.75 (16)C15—C14—H14A109.00
N12—C13—C14114.22 (14)C15—C14—H14B109.00
C13—C14—C15114.23 (16)H14A—C14—H14B108.00
C14—C15—C16114.64 (18)C14—C15—H15A109.00
C15—C16—C17114.77 (18)C14—C15—H15B109.00
C16—C17—C18113.52 (17)C16—C15—H15A109.00
N12—C18—C17116.96 (16)C16—C15—H15B109.00
O19—C18—N12122.76 (16)H15A—C15—H15B108.00
O19—C18—C17120.27 (16)C15—C16—H16A109.00
N1—C2—H2109.00C15—C16—H16B109.00
C3—C2—H2109.00C17—C16—H16A109.00
C11—C2—H2109.00C17—C16—H16B109.00
C2—C3—H3A110.00H16A—C16—H16B108.00
C2—C3—H3B110.00C16—C17—H17A109.00
C4—C3—H3A110.00C16—C17—H17B109.00
C4—C3—H3B110.00C18—C17—H17A109.00
H3A—C3—H3B108.00C18—C17—H17B109.00
N12—C4—H4107.00H17A—C17—H17B108.00
C3—C4—H4107.00
C10—N1—C2—C344.6 (2)C3—C4—C5—C6160.41 (16)
C10—N1—C2—C11168.08 (16)C3—C4—C5—C1022.4 (2)
C2—N1—C10—C516.6 (2)C4—C5—C6—C7176.99 (19)
C2—N1—C10—C9165.36 (16)C10—C5—C6—C70.2 (3)
C13—N12—C4—C356.10 (18)C4—C5—C10—N14.7 (2)
C13—N12—C4—C569.81 (17)C4—C5—C10—C9177.21 (15)
C18—N12—C4—C3127.62 (15)C6—C5—C10—N1178.05 (16)
C18—N12—C4—C5106.48 (16)C6—C5—C10—C90.0 (2)
C4—N12—C13—C14113.04 (16)C5—C6—C7—C80.5 (3)
C18—N12—C13—C1470.8 (2)C6—C7—C8—C90.5 (3)
C4—N12—C18—O191.8 (2)C7—C8—C9—C100.3 (3)
C4—N12—C18—C17179.65 (14)C8—C9—C10—N1178.00 (17)
C13—N12—C18—O19177.93 (15)C8—C9—C10—C50.1 (3)
C13—N12—C18—C173.5 (2)N12—C13—C14—C1579.6 (2)
N1—C2—C3—C460.77 (18)C13—C14—C15—C1656.7 (3)
C11—C2—C3—C4177.44 (16)C14—C15—C16—C1759.5 (3)
C2—C3—C4—N12176.30 (13)C15—C16—C17—C1883.3 (2)
C2—C3—C4—C549.92 (18)C16—C17—C18—O19112.4 (2)
N12—C4—C5—C633.7 (2)C16—C17—C18—N1266.2 (2)
N12—C4—C5—C10149.10 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O19i0.862.402.988 (2)126
C14—H14A···O19ii0.972.573.320 (2)134
Symmetry codes: (i) x+1/2, y+3/2, z1/2; (ii) x+1/2, y+1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O19i0.862.402.988 (2)126
C14—H14A···O19ii0.972.573.320 (2)134
Symmetry codes: (i) x+1/2, y+3/2, z1/2; (ii) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

The authors are thankful to IOE, Vijnana Bhavana, University of Mysore, Mysore, for providing the single-crystal X-ray diffractometer facility.

References

First citationBruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationKonishi, M., Ohkuma, H., Tsuno, T. & Oki, T. (1990). J. Am. Chem. Soc. 112, 3715–3716.  CSD CrossRef CAS Web of Science Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
Volume 70| Part 9| September 2014| Pages o981-o982
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