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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1498

4,7-Di­chloro­quinoline

aCollege of Pharmacy, Howard University, 2300 4th Street, NW, Washington, DC 2059, USA, and bDepartment of Chemistry, Howard University, 525 College Street, NW, Washington, DC 2059, USA
*Correspondence e-mail: amol.kulkarni@howard.edu

(Received 27 February 2012; accepted 4 April 2012; online 21 April 2012)

The two mol­ecules in the asymmetric unit of the title compound, C9H5Cl2N, are both essentially planar (r.m.s. deviations for all non-H atoms = 0.014 and 0.026 Å). There are no close C—H⋯Cl contacts.

Related literature

4,7-dichloro­quinoline is a commonly used starting material for the synthesis of a variety of anti-malarial drugs, such as amodiquine {systematic name: 4-[(7-chloro­quinolin-4-yl)amino]-2-[(diethyl­amino)­meth­yl]phenol}, see: Dongre et al. (2007[Dongre, V. G., Karmuse, P. P., Ghugare, P. D., Gupta, M., Nerurkar, B., Shaha, C. & Kumar, A. (2007). J. Pharm. Biomed. Anal. 43, 185-195.]); O'Neill et al. (2003[O'Neill, P. M., Mukhtar, A., Stocks, P. A., Randle, L. E., Hindley, S., Ward, S. A., Storr, R. C., Bickley, J. E., O'Neil, I. A., Maggs, J. L., Hughes, R. H., Winstanley, P. A., Bray, P. G. & Prak, B. K. (2003). J. Med. Chem. 46, 4993-4945.]); Lawrence et al. (2008[Lawrence, R. M., Dennis, K. C., O'Neill, P. M., Hahn, D. U., Roeder, M. & Struppe, C. (2008). Org. Process Res. Dev. 12, 294-297.]); Saha et al. (2009[Saha, C. N., Bhattacharya, S. & Chetia, D. (2009). Int. J. ChemTech Res. 1, 322-328.]).

[Scheme 1]

Experimental

Crystal data
  • C9H5Cl2N

  • Mr = 198.04

  • Monoclinic, P 21 /n

  • a = 18.2243 (17) Å

  • b = 3.8253 (5) Å

  • c = 23.622 (3) Å

  • β = 96.61 (1)°

  • V = 1635.8 (4) Å3

  • Z = 8

  • Cu Kα radiation

  • μ = 6.59 mm−1

  • T = 123 K

  • 0.35 × 0.23 × 0.16 mm

Data collection
  • Oxford Diffraction Xcalibur Ruby Gemini diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis PRO and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]) Tmin = 0.233, Tmax = 1.000

  • 5147 measured reflections

  • 3188 independent reflections

  • 2148 reflections with I > 2σ(I)

  • Rint = 0.090

Refinement
  • R[F2 > 2σ(F2)] = 0.096

  • wR(F2) = 0.327

  • S = 1.08

  • 3188 reflections

  • 217 parameters

  • H-atom parameters constrained

  • Δρmax = 0.68 e Å−3

  • Δρmin = −0.49 e Å−3

Data collection: CrysAlis PRO (Oxford Diffraction, 2007[Oxford Diffraction (2007). CrysAlis PRO and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The crystal structure of 4,7-dichloroquinoline has not previously been reported. Recrystallization of 4,7-dichloroquinoline from hexane or similar hydrocarbon solvents removes low levels (1–4%) of 4,5-dichloroquinoline that are present from the manufacturing process. Impurities that arise from the presence of 4,5-dichloroquinoline in 4,7-DCQ are otherwise difficult to remove from the manufacturing process of commercial malaria drugs, including amodiaquine and piperaquine (Dongre et al., 2007).

In view of the importance of this pharmaceutically active compound its crystal structure was determined. There are two molecules in the asymmetric unit (Z' = 2) and there are no close C—H···Cl contacts.

Related literature top

4,7-dichloroquinoline is a commonly used starting material for the synthesis of a variety of anti-malarial drugs, such as amodiquine {systematic name: 4-[(7-chloroquinolin-4-yl)amino]-2-[(diethylamino)methyl]phenol}, see: Dongre et al. (2007); O'Neill et al. (2003); Lawrence et al. (2008); Saha et al. (2009).

Experimental top

Hexanes (100 ml) were transferred to an Erlenmeyer flask and heated to a gentle reflux. 4,7-Dichloroquinoline (20 g, commercially available from Sigma-Aldrich) was slowly added to hexanes and the solution was maintained at 65 °C, resulting in a colorless solution. The solution was slowly cooled to room temperature and maintained at room temperature for 12 h. Long, colorless needles were observed to slowly crystallize from solution. The colorless needles obtained were isolated by filtration and dried to a constant weight, mp 83–84 °C; 1H-NMR (CDCl3) d 8.78 (d, J = 4.8 Hz, 1H), 8.15 (d, J = 9.2 Hz, 1H), 8.11 (d, J = 2.4 Hz, 1H), 7.59 (dd, J = 9.2, 2.4 Hz, 1H), 7.48 (d, J = 4.8 Hz, 1H).

Refinement top

H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with a C—H distance of 0.95Å and U(H) = 1.2Ueq(C).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); 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: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the title compound, C9H5Cl2N, showing atom numbering scheme and the two molecules in the asymmetric unit.
4,7-Dichloroquinoline top
Crystal data top
C9H5Cl2NF(000) = 800
Mr = 198.04Dx = 1.608 Mg m3
Monoclinic, P21/nCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ynCell parameters from 1283 reflections
a = 18.2243 (17) Åθ = 2.9–75.6°
b = 3.8253 (5) ŵ = 6.59 mm1
c = 23.622 (3) ÅT = 123 K
β = 96.61 (1)°Prism, colorless
V = 1635.8 (4) Å30.35 × 0.23 × 0.16 mm
Z = 8
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini
diffractometer
3188 independent reflections
Radiation source: Enhance (Cu) X-ray Source2148 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.090
Detector resolution: 10.5081 pixels mm-1θmax = 75.8°, θmin = 2.9°
ω scansh = 2216
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2007)
k = 44
Tmin = 0.233, Tmax = 1.000l = 2329
5147 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)] = 0.096Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.327H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.1577P)2 + 4.2615P]
where P = (Fo2 + 2Fc2)/3
3188 reflections(Δ/σ)max < 0.001
217 parametersΔρmax = 0.68 e Å3
0 restraintsΔρmin = 0.49 e Å3
Crystal data top
C9H5Cl2NV = 1635.8 (4) Å3
Mr = 198.04Z = 8
Monoclinic, P21/nCu Kα radiation
a = 18.2243 (17) ŵ = 6.59 mm1
b = 3.8253 (5) ÅT = 123 K
c = 23.622 (3) Å0.35 × 0.23 × 0.16 mm
β = 96.61 (1)°
Data collection top
Oxford Diffraction Xcalibur Ruby Gemini
diffractometer
3188 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2007)
2148 reflections with I > 2σ(I)
Tmin = 0.233, Tmax = 1.000Rint = 0.090
5147 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0960 restraints
wR(F2) = 0.327H-atom parameters constrained
S = 1.08Δρmax = 0.68 e Å3
3188 reflectionsΔρmin = 0.49 e Å3
217 parameters
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
xyzUiso*/Ueq
Cl1A0.46391 (11)0.7593 (6)0.94032 (9)0.0625 (6)
Cl2A0.31181 (11)0.9079 (6)0.65527 (9)0.0630 (6)
N1A0.5405 (3)0.4243 (18)0.7726 (3)0.0560 (15)
C2A0.5808 (4)0.369 (2)0.8223 (4)0.0544 (18)
H2AA0.62740.25810.82190.065*
C3A0.5587 (4)0.467 (2)0.8763 (4)0.0560 (18)
H3AA0.58920.41930.91080.067*
C4A0.4924 (4)0.6317 (19)0.8765 (3)0.0501 (16)
C5A0.3766 (4)0.8694 (19)0.8220 (4)0.0544 (18)
H5AA0.35790.94250.85600.065*
C6A0.3371 (4)0.9282 (19)0.7711 (4)0.0517 (17)
H6AA0.29061.04200.76940.062*
C7A0.3646 (4)0.822 (2)0.7200 (4)0.0541 (18)
C8A0.4305 (4)0.652 (2)0.7206 (4)0.0531 (17)
H8AA0.44750.57710.68600.064*
C9A0.4735 (4)0.5904 (19)0.7737 (4)0.0506 (16)
C10A0.4461 (4)0.6984 (18)0.8250 (3)0.0498 (16)
Cl1B0.50197 (10)0.9725 (5)0.58983 (9)0.0589 (6)
Cl2B0.80689 (11)0.2033 (5)0.48184 (10)0.0625 (6)
N1B0.7313 (3)0.6479 (18)0.6687 (3)0.0559 (16)
C2B0.6835 (4)0.802 (2)0.6981 (4)0.0569 (18)
H2BA0.69840.84630.73730.068*
C3B0.6115 (4)0.908 (2)0.6755 (4)0.0527 (17)
H3BA0.57971.01950.69910.063*
C4B0.5891 (4)0.848 (2)0.6205 (4)0.0528 (17)
C5B0.6209 (4)0.615 (2)0.5258 (4)0.0559 (19)
H5BA0.57300.66800.50770.067*
C6B0.6720 (4)0.472 (2)0.4941 (4)0.0539 (17)
H6BA0.66090.43090.45440.065*
C7B0.7417 (4)0.388 (2)0.5232 (4)0.0565 (19)
C8B0.7602 (4)0.439 (2)0.5800 (4)0.0527 (17)
H8BA0.80740.37000.59780.063*
C9B0.7092 (4)0.5951 (19)0.6121 (3)0.0483 (16)
C10B0.6378 (4)0.6840 (19)0.5843 (4)0.0526 (17)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl1A0.0557 (11)0.0571 (11)0.0757 (13)0.0000 (8)0.0113 (9)0.0010 (9)
Cl2A0.0476 (10)0.0611 (11)0.0788 (13)0.0022 (8)0.0012 (8)0.0029 (9)
N1A0.036 (3)0.050 (3)0.082 (4)0.002 (3)0.010 (3)0.001 (3)
C2A0.041 (4)0.049 (4)0.076 (5)0.001 (3)0.018 (3)0.002 (3)
C3A0.043 (4)0.044 (4)0.080 (5)0.004 (3)0.001 (3)0.008 (3)
C4A0.045 (4)0.044 (3)0.063 (4)0.005 (3)0.013 (3)0.005 (3)
C5A0.041 (4)0.038 (3)0.086 (5)0.002 (3)0.014 (3)0.004 (3)
C6A0.035 (3)0.044 (3)0.077 (5)0.001 (3)0.012 (3)0.001 (3)
C7A0.039 (4)0.045 (4)0.078 (5)0.005 (3)0.003 (3)0.004 (3)
C8A0.045 (4)0.043 (4)0.072 (5)0.002 (3)0.013 (3)0.007 (3)
C9A0.036 (3)0.039 (3)0.077 (5)0.004 (3)0.011 (3)0.001 (3)
C10A0.043 (4)0.038 (3)0.069 (4)0.005 (3)0.007 (3)0.002 (3)
Cl1B0.0374 (9)0.0560 (10)0.0837 (13)0.0058 (7)0.0087 (8)0.0054 (9)
Cl2B0.0474 (10)0.0558 (10)0.0875 (14)0.0036 (8)0.0205 (8)0.0008 (9)
N1B0.038 (3)0.049 (3)0.080 (4)0.002 (3)0.005 (3)0.006 (3)
C2B0.040 (4)0.047 (4)0.083 (5)0.002 (3)0.005 (3)0.006 (4)
C3B0.035 (3)0.052 (4)0.072 (5)0.004 (3)0.011 (3)0.004 (3)
C4B0.041 (4)0.044 (4)0.074 (5)0.005 (3)0.012 (3)0.011 (3)
C5B0.041 (4)0.050 (4)0.075 (5)0.008 (3)0.003 (3)0.011 (3)
C6B0.038 (4)0.058 (4)0.068 (5)0.004 (3)0.016 (3)0.001 (3)
C7B0.031 (3)0.048 (4)0.093 (6)0.003 (3)0.018 (3)0.005 (4)
C8B0.034 (3)0.044 (4)0.081 (5)0.001 (3)0.008 (3)0.002 (3)
C9B0.034 (3)0.042 (3)0.069 (4)0.002 (3)0.008 (3)0.006 (3)
C10B0.034 (3)0.040 (3)0.084 (5)0.002 (3)0.008 (3)0.006 (3)
Geometric parameters (Å, º) top
Cl1A—C4A1.720 (8)Cl1B—C4B1.734 (8)
Cl2A—C7A1.742 (8)Cl2B—C7B1.769 (8)
N1A—C2A1.328 (11)N1B—C2B1.313 (11)
N1A—C9A1.379 (10)N1B—C9B1.368 (10)
C2A—C3A1.432 (12)C2B—C3B1.418 (11)
C2A—H2AA0.9500C2B—H2BA0.9500
C3A—C4A1.362 (11)C3B—C4B1.338 (12)
C3A—H3AA0.9500C3B—H3BA0.9500
C4A—C10A1.422 (11)C4B—C10B1.443 (11)
C5A—C6A1.348 (12)C5B—C6B1.373 (12)
C5A—C10A1.420 (11)C5B—C10B1.407 (12)
C5A—H5AA0.9500C5B—H5BA0.9500
C6A—C7A1.417 (12)C6B—C7B1.410 (11)
C6A—H6AA0.9500C6B—H6BA0.9500
C7A—C8A1.364 (11)C7B—C8B1.359 (12)
C8A—C9A1.421 (11)C8B—C9B1.400 (11)
C8A—H8AA0.9500C8B—H8BA0.9500
C9A—C10A1.422 (11)C9B—C10B1.429 (10)
C2A—N1A—C9A117.2 (8)C2B—N1B—C9B116.3 (7)
N1A—C2A—C3A124.2 (7)N1B—C2B—C3B124.9 (8)
N1A—C2A—H2AA117.9N1B—C2B—H2BA117.6
C3A—C2A—H2AA117.9C3B—C2B—H2BA117.6
C4A—C3A—C2A117.7 (7)C4B—C3B—C2B118.8 (8)
C4A—C3A—H3AA121.1C4B—C3B—H3BA120.6
C2A—C3A—H3AA121.1C2B—C3B—H3BA120.6
C3A—C4A—C10A121.2 (8)C3B—C4B—C10B120.7 (7)
C3A—C4A—Cl1A119.5 (7)C3B—C4B—Cl1B121.4 (6)
C10A—C4A—Cl1A119.4 (6)C10B—C4B—Cl1B117.9 (6)
C6A—C5A—C10A120.2 (8)C6B—C5B—C10B121.7 (7)
C6A—C5A—H5AA119.9C6B—C5B—H5BA119.1
C10A—C5A—H5AA119.9C10B—C5B—H5BA119.1
C5A—C6A—C7A120.5 (7)C5B—C6B—C7B117.0 (8)
C5A—C6A—H6AA119.8C5B—C6B—H6BA121.5
C7A—C6A—H6AA119.8C7B—C6B—H6BA121.5
C8A—C7A—C6A121.7 (8)C8B—C7B—C6B123.7 (7)
C8A—C7A—Cl2A119.7 (7)C8B—C7B—Cl2B119.8 (6)
C6A—C7A—Cl2A118.6 (6)C6B—C7B—Cl2B116.5 (7)
C7A—C8A—C9A118.9 (8)C7B—C8B—C9B119.4 (7)
C7A—C8A—H8AA120.6C7B—C8B—H8BA120.3
C9A—C8A—H8AA120.6C9B—C8B—H8BA120.3
N1A—C9A—C8A117.3 (8)N1B—C9B—C8B117.0 (7)
N1A—C9A—C10A123.3 (7)N1B—C9B—C10B124.4 (7)
C8A—C9A—C10A119.5 (7)C8B—C9B—C10B118.7 (7)
C4A—C10A—C5A124.2 (8)C5B—C10B—C9B119.3 (7)
C4A—C10A—C9A116.4 (7)C5B—C10B—C4B125.8 (7)
C5A—C10A—C9A119.3 (7)C9B—C10B—C4B114.9 (7)
C9A—N1A—C2A—C3A0.9 (12)C9B—N1B—C2B—C3B1.5 (12)
N1A—C2A—C3A—C4A1.0 (12)N1B—C2B—C3B—C4B0.3 (12)
C2A—C3A—C4A—C10A1.1 (11)C2B—C3B—C4B—C10B1.2 (11)
C2A—C3A—C4A—Cl1A179.2 (6)C2B—C3B—C4B—Cl1B179.5 (6)
C10A—C5A—C6A—C7A0.2 (11)C10B—C5B—C6B—C7B1.7 (12)
C5A—C6A—C7A—C8A1.1 (12)C5B—C6B—C7B—C8B0.4 (12)
C5A—C6A—C7A—Cl2A179.4 (6)C5B—C6B—C7B—Cl2B179.9 (6)
C6A—C7A—C8A—C9A1.7 (11)C6B—C7B—C8B—C9B2.4 (12)
Cl2A—C7A—C8A—C9A178.8 (6)Cl2B—C7B—C8B—C9B178.1 (6)
C2A—N1A—C9A—C8A179.4 (7)C2B—N1B—C9B—C8B178.4 (7)
C2A—N1A—C9A—C10A0.9 (11)C2B—N1B—C9B—C10B2.5 (11)
C7A—C8A—C9A—N1A178.8 (7)C7B—C8B—C9B—N1B178.5 (7)
C7A—C8A—C9A—C10A1.4 (11)C7B—C8B—C9B—C10B2.3 (11)
C3A—C4A—C10A—C5A179.7 (7)C6B—C5B—C10B—C9B1.7 (11)
Cl1A—C4A—C10A—C5A0.5 (10)C6B—C5B—C10B—C4B177.0 (7)
C3A—C4A—C10A—C9A1.1 (11)N1B—C9B—C10B—C5B179.5 (7)
Cl1A—C4A—C10A—C9A179.2 (5)C8B—C9B—C10B—C5B0.3 (11)
C6A—C5A—C10A—C4A178.6 (7)N1B—C9B—C10B—C4B1.7 (11)
C6A—C5A—C10A—C9A0.0 (11)C8B—C9B—C10B—C4B179.2 (7)
N1A—C9A—C10A—C4A1.0 (10)C3B—C4B—C10B—C5B178.5 (7)
C8A—C9A—C10A—C4A179.3 (7)Cl1B—C4B—C10B—C5B0.1 (10)
N1A—C9A—C10A—C5A179.7 (7)C3B—C4B—C10B—C9B0.3 (10)
C8A—C9A—C10A—C5A0.6 (10)Cl1B—C4B—C10B—C9B178.6 (5)

Experimental details

Crystal data
Chemical formulaC9H5Cl2N
Mr198.04
Crystal system, space groupMonoclinic, P21/n
Temperature (K)123
a, b, c (Å)18.2243 (17), 3.8253 (5), 23.622 (3)
β (°) 96.61 (1)
V3)1635.8 (4)
Z8
Radiation typeCu Kα
µ (mm1)6.59
Crystal size (mm)0.35 × 0.23 × 0.16
Data collection
DiffractometerOxford Diffraction Xcalibur Ruby Gemini
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Oxford Diffraction, 2007)
Tmin, Tmax0.233, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
5147, 3188, 2148
Rint0.090
(sin θ/λ)max1)0.629
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.096, 0.327, 1.08
No. of reflections3188
No. of parameters217
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.68, 0.49

Computer programs: CrysAlis PRO (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

 

Acknowledgements

AAK wishes to acknowledge RCMI, Howard University and the CDRD, College of Pharmacy, Howard University. RJB wishes to acknowledge the NSF–MRI program (grant CHE-0619278) for funds to purchase the diffractometer. This project was supported by grant No. D34HP16042-03-03 from the Health Resources and Services Administration (HRSA).

References

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Volume 68| Part 5| May 2012| Page o1498
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