8-Chloro-2-methyl­quinoline

Abstract

In the title compound, C₁₀H₈ClN, the crystal packing shows π–π stacking between the heterocyclic ring and the aromatic ring, with a centroid–centroid distance of 3.819 Å. The crystal studied was a racemic twin, the ratio of the twin components being 0.65 (7):0.35 (7).

Related literature

The title compound is an important inter­mediate in the pharmaceutical industry, see: Shen & Hartwig (2006 ▶); Ranu et al. (2000 ▶); Lee & Hartwig (2005 ▶).

Experimental

Crystal data

• C₁₀H₈ClN

• M _r = 177.62

• Orthorhombic,

• a = 12.7961 (9) Å

• b = 5.0660 (4) Å

• c = 13.1181 (9) Å

• V = 850.38 (11) ų

• Z = 4

• Mo Kα radiation

• μ = 0.39 mm⁻¹

• T = 173 K

• 0.47 × 0.46 × 0.23 mm

Data collection

• Bruker SMART 1000 CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.840, T _max = 0.917

• 3943 measured reflections

• 1821 independent reflections

• 1703 reflections with I > 2σ(I)

• R _int = 0.016

Refinement

• R[F ² > 2σ(F ²)] = 0.029

• wR(F ²) = 0.075

• S = 1.09

• 1821 reflections

• 111 parameters

• 1 restraint

• H-atom parameters constrained

• Δρ_max = 0.20 e Å⁻³

• Δρ_min = −0.16 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2003 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

The structure of the title compound, 8-chloro-2-methylquinoline, is shown in Fig 1. It is an important intermediate of medecine industry (Shen et al., 2006; Ranu et al., 2000; Lee et al., 2005). The crystal packing shows π-π stacking between the N containing aromatic ring and the aromatic ring with the chloro substituent with a centroid-centroid distance of 3.819Å.

Experimental

A solution of 13 g of 2-chloroaniline in 200 mL chlorobenzene and 0.5 g of p-toluenesulfonic acid was heated to 393 K. 14 g of crotonaldehyde were added dropwise with in 1 h, then refluxed for 2 h. The solution was concentrated under reduced pressure to give rude product, which was then recrystallizated from dimethylbenzene to get 10 g of the product as a white solid. The yield was 57%. Crystals suitable for X-ray structure determination were obtained by slow evaporation of an ethanol solution at room temperature.

Refinement

H atom were positioned geometrically (C_aromatic—H = 0.95 Å, C_methyl—H = 0.98 Å) and refined as riding with U_iso(H) = 1.2U_eq(C_aromatic) or U_iso(H) = 1.5U_eq(C_methyl). The crystal under investigation turned out to be a racemic twin with a ratio of the twin components of 0.65 (7) to 0.35 (7).

Figures

Fig. 1.

Molecular structure of the title compound showing 50% probability displacement ellipsoids.

Crystal data

C10H8ClN	Dx = 1.387 Mg m−3
Mr = 177.62	Melting point: 333 K
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 2761 reflections
a = 12.7961 (9) Å	θ = 3.1–27.0°
b = 5.0660 (4) Å	µ = 0.39 mm−1
c = 13.1181 (9) Å	T = 173 K
V = 850.38 (11) Å3	Block, colourless
Z = 4	0.47 × 0.46 × 0.23 mm
F(000) = 368

Data collection

Bruker SMART 1000 CCD diffractometer	1821 independent reflections
Radiation source: fine-focus sealed tube	1703 reflections with I > 2σ(I)
graphite	Rint = 0.016
ω scans	θmax = 27.1°, θmin = 3.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −16→16
Tmin = 0.840, Tmax = 0.917	k = −2→6
3943 measured reflections	l = −15→16

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.075	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0403P)2 + 0.17P] where P = (Fo2 + 2Fc2)/3
1821 reflections	(Δ/σ)max = 0.004
111 parameters	Δρmax = 0.20 e Å−3
1 restraint	Δρmin = −0.16 e Å−3

Special details

Experimental. MS (m/z):M+ 177. 1H NMR(CDCl3,400 MHz,delta dppm): 2.83(s,3H,CH3), 7.38(m,2H,quinoline 3,6-H), 7.80(d, J=7.2 Hz,1H, quinoline 7-H),8.03(d, J =8.0 Hz,1H,quinoline 5-H), 8.00(d,J = 8.4 Hz, 1H,quinoline 4-H)

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.13075 (3)	−0.06692 (9)	−0.13065 (4)	0.03616 (14)
C1	0.33097 (14)	0.5106 (4)	0.00528 (15)	0.0286 (4)
C2	0.33961 (16)	0.5667 (4)	0.11114 (16)	0.0336 (4)
H2	0.3873	0.6971	0.1345	0.040*
C3	0.27923 (15)	0.4323 (3)	0.17875 (15)	0.0323 (4)
H3	0.2846	0.4675	0.2497	0.039*
C4	0.20807 (14)	0.2386 (3)	0.14243 (14)	0.0277 (4)
C5	0.14115 (15)	0.0969 (4)	0.20801 (15)	0.0327 (4)
H5	0.1427	0.1293	0.2793	0.039*
C6	0.07432 (15)	−0.0864 (4)	0.16908 (16)	0.0349 (4)
H6	0.0285	−0.1792	0.2134	0.042*
C7	0.07260 (15)	−0.1394 (4)	0.06385 (16)	0.0330 (4)
H7	0.0266	−0.2701	0.0377	0.040*
C8	0.13698 (14)	−0.0033 (4)	−0.00123 (15)	0.0271 (4)
C9	0.20665 (13)	0.1930 (3)	0.03548 (13)	0.0248 (3)
C10	0.39634 (17)	0.6615 (5)	−0.06992 (17)	0.0393 (5)
H10A	0.4700	0.6137	−0.0613	0.059*
H10B	0.3877	0.8513	−0.0582	0.059*
H10C	0.3740	0.6181	−0.1394	0.059*
N1	0.26803 (12)	0.3289 (3)	−0.03180 (11)	0.0268 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0393 (2)	0.0441 (3)	0.0251 (2)	−0.00280 (19)	−0.0036 (2)	−0.0074 (2)
C1	0.0279 (9)	0.0261 (8)	0.0319 (10)	0.0032 (7)	−0.0008 (8)	0.0037 (7)
C2	0.0343 (10)	0.0291 (10)	0.0374 (11)	−0.0015 (8)	−0.0081 (8)	−0.0030 (8)
C3	0.0397 (10)	0.0305 (9)	0.0266 (9)	0.0039 (8)	−0.0052 (8)	−0.0054 (7)
C4	0.0320 (9)	0.0253 (9)	0.0259 (9)	0.0060 (7)	−0.0009 (7)	−0.0001 (7)
C5	0.0412 (10)	0.0344 (10)	0.0223 (9)	0.0063 (8)	0.0002 (8)	0.0031 (7)
C6	0.0339 (10)	0.0382 (11)	0.0325 (10)	−0.0010 (8)	0.0045 (8)	0.0086 (8)
C7	0.0297 (9)	0.0334 (10)	0.0360 (10)	−0.0033 (8)	−0.0023 (8)	0.0029 (8)
C8	0.0294 (9)	0.0310 (8)	0.0209 (9)	0.0033 (7)	−0.0029 (7)	−0.0013 (7)
C9	0.0253 (8)	0.0245 (8)	0.0247 (9)	0.0056 (7)	−0.0025 (7)	0.0005 (6)
C10	0.0408 (10)	0.0375 (10)	0.0396 (12)	−0.0067 (10)	0.0004 (9)	0.0082 (9)
N1	0.0265 (7)	0.0274 (7)	0.0264 (8)	0.0039 (6)	0.0013 (6)	0.0030 (6)

Geometric parameters (Å, °)

Cl1—C8	1.730 (2)	C5—H5	0.9500
C1—N1	1.316 (3)	C6—C7	1.407 (3)
C1—C2	1.422 (3)	C6—H6	0.9500
C1—C10	1.503 (3)	C7—C8	1.372 (3)
C2—C3	1.359 (3)	C7—H7	0.9500
C2—H2	0.9500	C8—C9	1.420 (3)
C3—C4	1.421 (2)	C9—N1	1.367 (2)
C3—H3	0.9500	C10—H10A	0.9800
C4—C5	1.410 (3)	C10—H10B	0.9800
C4—C9	1.422 (2)	C10—H10C	0.9800
C5—C6	1.362 (3)
N1—C1—C2	123.25 (18)	C7—C6—H6	119.7
N1—C1—C10	116.99 (18)	C8—C7—C6	120.36 (18)
C2—C1—C10	119.76 (18)	C8—C7—H7	119.8
C3—C2—C1	119.55 (18)	C6—C7—H7	119.8
C3—C2—H2	120.2	C7—C8—C9	121.19 (18)
C1—C2—H2	120.2	C7—C8—Cl1	119.30 (15)
C2—C3—C4	119.44 (18)	C9—C8—Cl1	119.49 (15)
C2—C3—H3	120.3	N1—C9—C8	119.62 (16)
C4—C3—H3	120.3	N1—C9—C4	123.21 (16)
C5—C4—C3	122.42 (17)	C8—C9—C4	117.16 (16)
C5—C4—C9	120.76 (17)	C1—C10—H10A	109.5
C3—C4—C9	116.82 (16)	C1—C10—H10B	109.5
C6—C5—C4	119.98 (18)	H10A—C10—H10B	109.5
C6—C5—H5	120.0	C1—C10—H10C	109.5
C4—C5—H5	120.0	H10A—C10—H10C	109.5
C5—C6—C7	120.54 (18)	H10B—C10—H10C	109.5
C5—C6—H6	119.7	C1—N1—C9	117.70 (16)
N1—C1—C2—C3	−1.4 (3)	Cl1—C8—C9—N1	−0.1 (2)
C10—C1—C2—C3	179.05 (18)	C7—C8—C9—C4	1.1 (2)
C1—C2—C3—C4	−0.3 (3)	Cl1—C8—C9—C4	179.55 (13)
C2—C3—C4—C5	−178.29 (18)	C5—C4—C9—N1	178.44 (15)
C2—C3—C4—C9	1.5 (2)	C3—C4—C9—N1	−1.4 (2)
C3—C4—C5—C6	179.90 (17)	C5—C4—C9—C8	−1.2 (2)
C9—C4—C5—C6	0.1 (3)	C3—C4—C9—C8	178.99 (15)
C4—C5—C6—C7	1.1 (3)	C2—C1—N1—C9	1.5 (3)
C5—C6—C7—C8	−1.2 (3)	C10—C1—N1—C9	−178.87 (16)
C6—C7—C8—C9	0.1 (3)	C8—C9—N1—C1	179.50 (16)
C6—C7—C8—Cl1	−178.36 (15)	C4—C9—N1—C1	−0.1 (2)
C7—C8—C9—N1	−178.55 (17)