2-[(2-Chloro­phenyl)­imino­methyl]-4,6-di­methyl­quinoline

The mol­ecule of the title compound, C₁₈H₁₅ClN₂, is not planar. The dihedral angle between the quinoline and phenyl rings is 116.2 (1)°. Bond lengths and angles are normal.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.071
• wR factor = 0.217
• Data-to-parameter ratio = 17.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



PLAT_030  Alert B Refined Extinction parameter within range ....       2.00 Sigma


 0 Alert Level A = Potentially serious problem

 1 Alert Level B = Potential problem

 0 Alert Level C = Please check

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S1. Comment

Schiff bases, occupying an important place in medicine and industry, are generally useful compounds as starting materials in the preparation of textile, dyestuffs, pesticides and pharmaceuticals, and of compounds that serve as stabilizers and inhibitors in photography (Sommes, 1976). Great attention has been recently begun to concentrate on the compounds obtained from heterocyclic carbaldehydes for the therapy of cancer, the disease of our age (Kouznetsov et al., 1998; Öcal & Kaban, 1998). Hence, in our research, new Schiff bases containing different functional groups have been synthesized for the purpose of making some contributions to that class of substances which are now being tried as anticancer reagents.

This structure of the title compound, 4,6-Dimethylquinoline-2-[N-(o-chlorophenyl)formimidoyl], (I), is isomorphous with 4,6-dimethylquinoline-2-[N-(o-tolyl)formimidoyl], (II) (Akkurt et al., 2001). The quinoline and phenyl rings are planar. In the quinoline ring, the C3—C4—C5 angle is bigger than 120° [124.0 (3)°] and the N1—C9—C8 angle is smaller than 120° [118.4 (3)°]. Corresponding values are almostly comparable with the ones in 3-(p-chlorophenyl)-5-methyl-2-(8-quinolinyl)-4-thiazolidinone (Öztürk et al., 2000) [for molecule A of two independent molecules in the asymmetric unit, 122.8 (6) and 120.3 (5)°, respectively, and for the molecule B, 124.4 (7) and 117.4 (4)°, respectively] and in (II) [123.4 (2) and 118.2 (2)°, respectively]. The fold angles between the least-squares planes of the quinoline and phenyl rings are 116.2 (1) and 118.5 (1)° in (II) and 61.8 (1)° in N-8-azanaphtylmethylene-4-chloroaniline (Öztürk et al., 2001). This large deviation is possibly due to the steric factors which occur the different position of the Cl atom in the phenyl ring. There are non-bonded contacts > 3.3 Å between non-H atoms.

S2. Experimental

The title compound was synthesized by the condensation of 4,6-dimethylquinoline-2-carbaldehyde with o-chloroaniline in dry benzene over a period of 11 h. Light-yellow crystals were obtained after crystallization from petroleum ether (313–333 K). Yield: 81%; m.p.: 405 K; IR (KBr): γ = 3030, 2900, 1580 cm^-1; ¹H NMR (CDCl₃, δ, 200 MHz): 2.58 (3H, s, 6-CH₃), 2.74 (3H, s, 4-CH₃), 7.12–8.65 (9H, m, ArH and CH) p.p.m.; UV (CHCl₃): λ_max = 262.3, 314.4 nm. Elemental analysis, C₁₈H₁₅N₂ requires: C 73.34, H 5.13, N 9.50%; found: C 73.18, H 5.07, N 9.43% (Aydo~gan, 1993).

S3. Refinement

The methyl groups were allowed to rotate about their local threefold axes.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).

Figures

	Fig. 1. An ORTEPII (Johnson, 1976) drawing of the title compound showing the labelling of the non-H atoms. Displacement ellipsoids are shown at the 50% probability level.
	Fig. 2. A view of unit cell along the a axis.

2-[(2-Chlorophenyl)iminomethyl]-4,6-dimethylquinoline

Crystal data

C18H15ClN2	Z = 2
Mr = 294.77	F(000) = 308
Triclinic, P1	Dx = 1.278 Mg m^−3
a = 7.4962 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.5511 (9) Å	Cell parameters from 1530 reflections
c = 11.4013 (11) Å	θ = 2.8–27.5°
α = 79.039 (2)°	µ = 0.24 mm^−1
β = 76.866 (2)°	T = 293 K
γ = 76.886 (2)°	Needle, light yellow
V = 765.90 (13) Å^3	0.34 × 0.22 × 0.10 mm

Data collection

Siemens SMART 1000 CCD area-detector diffractometer	3363 independent reflections
Radiation source: fine-focus sealed tube	1573 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 8.33 pixels mm^-1	θmax = 27.5°, θmin = 2.8°
ω scans	h = −8→9
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −12→12
Tmin = 0.922, Tmax = 0.976	l = −12→14
4930 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.071	H-atom parameters constrained
wR(F^2) = 0.217	w = 1/[σ^2(Fo^2) + (0.0995P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.98	(Δ/σ)max = 0.006
3363 reflections	Δρmax = 0.24 e Å^−3
193 parameters	Δρmin = −0.29 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.012 (6)

Special details

Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different ϕ angle (0, 88 and 180°) for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal-to-detector distance was 4 cm and the detector swing angle was -35°. Coverage of the unique set is over 99% complete. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analysing the duplicate reflections, and was found to be negligible.

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	0.09265 (15)	0.64820 (14)	0.13413 (10)	0.0847 (5)
N1	−0.2795 (4)	0.1499 (3)	0.2679 (3)	0.0529 (8)
N2	−0.2447 (4)	0.5196 (3)	0.2078 (3)	0.0557 (8)
C1	−0.2753 (5)	0.2763 (4)	0.2971 (3)	0.0504 (9)
C2	−0.2659 (5)	0.2931 (4)	0.4162 (3)	0.0535 (9)
H2B	−0.2652	0.3846	0.4327	0.064*
C3	−0.2581 (5)	0.1783 (4)	0.5066 (3)	0.0496 (9)
C4	−0.2561 (4)	0.0402 (4)	0.4773 (3)	0.0467 (8)
C5	−0.2413 (5)	−0.0895 (4)	0.5605 (3)	0.0558 (9)
H5A	−0.2324	−0.0855	0.6398	0.067*
C6	−0.2397 (5)	−0.2211 (4)	0.5288 (4)	0.0608 (10)
C7	−0.2565 (5)	−0.2259 (4)	0.4094 (4)	0.0635 (11)
H7A	−0.2580	−0.3145	0.3874	0.076*
C8	−0.2707 (5)	−0.1043 (4)	0.3256 (4)	0.0614 (10)
H8A	−0.2811	−0.1108	0.2471	0.074*
C9	−0.2699 (4)	0.0319 (4)	0.3562 (3)	0.0496 (9)
C10	−0.2508 (6)	0.1982 (4)	0.6332 (3)	0.0664 (11)
H10A	−0.2508	0.2984	0.6347	0.100*
H10B	−0.1391	0.1388	0.6565	0.100*
H10C	−0.3578	0.1702	0.6891	0.100*
C11	−0.2192 (7)	−0.3590 (4)	0.6193 (4)	0.0807 (13)
H11A	−0.2231	−0.3352	0.6980	0.121*
H11B	−0.1021	−0.4211	0.5935	0.121*
H11C	−0.3195	−0.4081	0.6236	0.121*
C12	−0.2763 (5)	0.3988 (4)	0.1977 (3)	0.0545 (9)
H12A	−0.3013	0.3869	0.1243	0.065*
C13	−0.2514 (5)	0.6330 (4)	0.1083 (3)	0.0509 (9)
C14	−0.4048 (6)	0.6813 (5)	0.0530 (4)	0.0702 (11)
H14A	−0.5047	0.6329	0.0773	0.084*
C15	−0.4128 (8)	0.7990 (5)	−0.0371 (4)	0.0865 (14)
H15A	−0.5184	0.8311	−0.0720	0.104*
C16	−0.2639 (8)	0.8698 (5)	−0.0757 (4)	0.0865 (14)
H16A	−0.2686	0.9491	−0.1373	0.104*
C17	−0.1083 (7)	0.8233 (5)	−0.0232 (4)	0.0714 (12)
H17A	−0.0077	0.8708	−0.0490	0.086*
C18	−0.1035 (5)	0.7061 (4)	0.0676 (3)	0.0550 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0617 (7)	0.1274 (11)	0.0706 (8)	−0.0348 (6)	−0.0137 (5)	−0.0067 (7)
N1	0.0569 (18)	0.0596 (19)	0.0461 (18)	−0.0206 (15)	−0.0049 (13)	−0.0116 (16)
N2	0.061 (2)	0.0602 (19)	0.0485 (19)	−0.0228 (16)	−0.0107 (14)	−0.0018 (15)
C1	0.051 (2)	0.055 (2)	0.046 (2)	−0.0164 (18)	−0.0059 (16)	−0.0075 (18)
C2	0.062 (2)	0.055 (2)	0.050 (2)	−0.0259 (19)	−0.0080 (17)	−0.0100 (18)
C3	0.054 (2)	0.059 (2)	0.040 (2)	−0.0238 (18)	−0.0067 (15)	−0.0050 (18)
C4	0.0415 (19)	0.049 (2)	0.050 (2)	−0.0145 (16)	−0.0058 (15)	−0.0063 (17)
C5	0.052 (2)	0.061 (2)	0.053 (2)	−0.0162 (18)	−0.0046 (17)	−0.0050 (19)
C6	0.051 (2)	0.055 (2)	0.072 (3)	−0.0130 (18)	−0.0044 (19)	−0.006 (2)
C7	0.066 (3)	0.049 (2)	0.077 (3)	−0.014 (2)	−0.007 (2)	−0.016 (2)
C8	0.065 (2)	0.062 (2)	0.062 (3)	−0.020 (2)	−0.0022 (19)	−0.022 (2)
C9	0.046 (2)	0.053 (2)	0.052 (2)	−0.0165 (17)	−0.0038 (16)	−0.0094 (18)
C10	0.092 (3)	0.063 (2)	0.055 (2)	−0.027 (2)	−0.023 (2)	−0.008 (2)
C11	0.085 (3)	0.058 (3)	0.092 (3)	−0.016 (2)	−0.014 (3)	0.005 (2)
C12	0.058 (2)	0.067 (2)	0.041 (2)	−0.0226 (19)	−0.0085 (16)	−0.0038 (18)
C13	0.055 (2)	0.055 (2)	0.043 (2)	−0.0136 (18)	−0.0064 (17)	−0.0096 (18)
C14	0.066 (3)	0.081 (3)	0.068 (3)	−0.019 (2)	−0.024 (2)	−0.003 (2)
C15	0.096 (4)	0.082 (3)	0.080 (3)	0.002 (3)	−0.040 (3)	−0.002 (3)
C16	0.123 (4)	0.070 (3)	0.058 (3)	−0.014 (3)	−0.020 (3)	0.008 (2)
C17	0.091 (3)	0.070 (3)	0.050 (2)	−0.033 (2)	0.006 (2)	−0.004 (2)
C18	0.060 (2)	0.063 (2)	0.043 (2)	−0.0200 (19)	−0.0018 (16)	−0.0087 (19)

Geometric parameters (Å, º)

Cl1—C18	1.738 (4)	C8—C9	1.411 (5)
N1—C1	1.321 (4)	C8—H8A	0.9300
N1—C9	1.361 (4)	C10—H10A	0.9600
N2—C12	1.260 (4)	C10—H10B	0.9600
N2—C13	1.413 (4)	C10—H10C	0.9600
C1—C2	1.416 (5)	C11—H11A	0.9600
C1—C12	1.466 (5)	C11—H11B	0.9600
C2—C3	1.355 (5)	C11—H11C	0.9600
C2—H2B	0.9300	C12—H12A	0.9300
C3—C4	1.418 (4)	C13—C14	1.382 (5)
C3—C10	1.505 (5)	C13—C18	1.389 (5)
C4—C5	1.408 (5)	C14—C15	1.372 (6)
C4—C9	1.427 (5)	C14—H14A	0.9300
C5—C6	1.369 (5)	C15—C16	1.379 (7)
C5—H5A	0.9300	C15—H15A	0.9300
C6—C7	1.405 (5)	C16—C17	1.377 (6)
C6—C11	1.512 (5)	C16—H16A	0.9300
C7—C8	1.357 (5)	C17—C18	1.372 (5)
C7—H7A	0.9300	C17—H17A	0.9300
C1—N1—C9	117.8 (3)	H10A—C10—H10B	109.5
C12—N2—C13	119.0 (3)	C3—C10—H10C	109.5
N1—C1—C2	122.5 (3)	H10A—C10—H10C	109.5
N1—C1—C12	115.9 (3)	H10B—C10—H10C	109.5
C2—C1—C12	121.6 (3)	C6—C11—H11A	109.5
C3—C2—C1	121.3 (3)	C6—C11—H11B	109.5
C3—C2—H2B	119.4	H11A—C11—H11B	109.5
C1—C2—H2B	119.4	C6—C11—H11C	109.5
C2—C3—C4	117.7 (3)	H11A—C11—H11C	109.5
C2—C3—C10	120.7 (3)	H11B—C11—H11C	109.5
C4—C3—C10	121.7 (3)	N2—C12—C1	122.5 (3)
C5—C4—C3	124.0 (3)	N2—C12—H12A	118.7
C5—C4—C9	118.0 (3)	C1—C12—H12A	118.7
C3—C4—C9	118.0 (3)	C14—C13—C18	117.6 (4)
C6—C5—C4	122.4 (4)	C14—C13—N2	122.9 (3)
C6—C5—H5A	118.8	C18—C13—N2	119.5 (3)
C4—C5—H5A	118.8	C15—C14—C13	121.4 (4)
C5—C6—C7	118.5 (4)	C15—C14—H14A	119.3
C5—C6—C11	121.2 (4)	C13—C14—H14A	119.3
C7—C6—C11	120.3 (4)	C14—C15—C16	119.8 (4)
C8—C7—C6	121.5 (3)	C14—C15—H15A	120.1
C8—C7—H7A	119.2	C16—C15—H15A	120.1
C6—C7—H7A	119.2	C17—C16—C15	120.2 (4)
C7—C8—C9	120.7 (4)	C17—C16—H16A	119.9
C7—C8—H8A	119.6	C15—C16—H16A	119.9
C9—C8—H8A	119.6	C16—C17—C18	119.2 (4)
N1—C9—C8	118.4 (3)	C16—C17—H17A	120.4
N1—C9—C4	122.7 (3)	C18—C17—H17A	120.4
C8—C9—C4	118.9 (3)	C17—C18—C13	121.8 (4)
C3—C10—H10A	109.5	C17—C18—Cl1	119.1 (3)
C3—C10—H10B	109.5	C13—C18—Cl1	119.0 (3)
C9—N1—C1—C2	−1.5 (5)	C5—C4—C9—N1	−178.1 (3)
C9—N1—C1—C12	177.0 (3)	C3—C4—C9—N1	1.9 (5)
N1—C1—C2—C3	0.9 (5)	C5—C4—C9—C8	0.8 (5)
C12—C1—C2—C3	−177.5 (3)	C3—C4—C9—C8	−179.2 (3)
C1—C2—C3—C4	1.1 (5)	C13—N2—C12—C1	−178.9 (3)
C1—C2—C3—C10	−179.1 (3)	N1—C1—C12—N2	−169.1 (3)
C2—C3—C4—C5	177.6 (3)	C2—C1—C12—N2	9.5 (5)
C10—C3—C4—C5	−2.1 (5)	C12—N2—C13—C14	54.7 (5)
C2—C3—C4—C9	−2.4 (5)	C12—N2—C13—C18	−129.3 (4)
C10—C3—C4—C9	177.9 (3)	C18—C13—C14—C15	−1.4 (6)
C3—C4—C5—C6	−179.9 (3)	N2—C13—C14—C15	174.7 (4)
C9—C4—C5—C6	0.1 (5)	C13—C14—C15—C16	1.3 (7)
C4—C5—C6—C7	−1.1 (5)	C14—C15—C16—C17	−0.6 (7)
C4—C5—C6—C11	178.6 (3)	C15—C16—C17—C18	0.0 (7)
C5—C6—C7—C8	1.2 (6)	C16—C17—C18—C13	−0.1 (6)
C11—C6—C7—C8	−178.4 (4)	C16—C17—C18—Cl1	−179.7 (3)
C6—C7—C8—C9	−0.3 (6)	C14—C13—C18—C17	0.8 (5)
C1—N1—C9—C8	−178.8 (3)	N2—C13—C18—C17	−175.5 (3)
C1—N1—C9—C4	0.1 (5)	C14—C13—C18—Cl1	−179.6 (3)
C7—C8—C9—N1	178.3 (3)	N2—C13—C18—Cl1	4.1 (4)
C7—C8—C9—C4	−0.7 (5)