Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807054475/at2458sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807054475/at2458Isup2.hkl |
CCDC reference: 672810
Key indicators
- Single-crystal X-ray study
- T = 200 K
- Mean (C-C) = 0.002 Å
- R factor = 0.044
- wR factor = 0.135
- Data-to-parameter ratio = 24.0
checkCIF/PLATON results
No syntax errors found
Alert level C ABSTM02_ALERT_3_C The ratio of expected to reported Tmax/Tmin(RR') is < 0.90 Tmin and Tmax reported: 0.723 1.000 Tmin(prime) and Tmax expected: 0.807 0.914 RR(prime) = 0.819 Please check that your absorption correction is appropriate. PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large ............. 0.81 PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.91
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.914 Tmax scaled 0.914 Tmin scaled 0.661
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 3 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
3-methylquinoxalin-2(1H)-one (5.0 g, 0.0312 mol) was added to cold phosphorus oxychloride (41.0 g, 0.26 mol) in portions to get a slurry. To the resulting slurry N,N-Dimethyl aniline (0.95 g, 0.0078 mol) was added drop wise below 288 K. The brick red mixture was refluxed (at approx. 378 K) for 15 min and the resulting dark brown clear solution was then cooled to ambient temperature. It was added to ice cold water (250 ml) and basified slowly under cooling with 40% aq. NaOH to pH 8. The brick red solid, thus separated was filtered, washed with water (2x50 ml) and dried to obtain crude 2-chloro-3-methylquinoxaline. The crude product was dissolved in hot hexane (75 ml), treated with activated charcoal and filtered. The filtrate on concentration to a small volume (5 ml) gave pure 2-chloro-3-methylquinoxaline, as brick red crystals, which was further recrystalized from acetone to get colourless crystals, 4.0 g (72%).
H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95 or 0.98 Å and Uiso=1.2 or1.5 times Ueq(C).
Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis CCD (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: PLATON (Spek, 2003).
Fig. 1. The molecular structure of the title compound with the atomic numbering and 50% probability displacement ellipsoids. H atoms are shown shown as small spheres of arbitrary radius. |
C9H7ClN2 | Z = 2 |
Mr = 178.62 | F(000) = 184 |
Triclinic, P1 | Dx = 1.472 Mg m−3 |
Hall symbol: -P 1 | Melting point: 352(1) K |
a = 6.8876 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.4022 (4) Å | Cell parameters from 3999 reflections |
c = 9.4124 (5) Å | θ = 4.7–32.3° |
α = 70.654 (4)° | µ = 0.41 mm−1 |
β = 72.438 (5)° | T = 200 K |
γ = 65.019 (5)° | Square-plate, pale-pink |
V = 403.01 (4) Å3 | 0.51 × 0.49 × 0.22 mm |
Oxford Diffraction Gemini diffractometer | 2645 independent reflections |
Radiation source: fine-focus sealed tube | 2094 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
Detector resolution: 10.5081 pixels mm-1 | θmax = 32.4°, θmin = 4.7° |
ϕ and ω scans | h = −9→10 |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007) | k = −10→11 |
Tmin = 0.723, Tmax = 1.000 | l = −8→14 |
5962 measured reflections |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.135 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0789P)2 + 0.0905P] where P = (Fo2 + 2Fc2)/3 |
2645 reflections | (Δ/σ)max < 0.001 |
110 parameters | Δρmax = 0.51 e Å−3 |
0 restraints | Δρmin = −0.31 e Å−3 |
C9H7ClN2 | γ = 65.019 (5)° |
Mr = 178.62 | V = 403.01 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.8876 (4) Å | Mo Kα radiation |
b = 7.4022 (4) Å | µ = 0.41 mm−1 |
c = 9.4124 (5) Å | T = 200 K |
α = 70.654 (4)° | 0.51 × 0.49 × 0.22 mm |
β = 72.438 (5)° |
Oxford Diffraction Gemini diffractometer | 2645 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007) | 2094 reflections with I > 2σ(I) |
Tmin = 0.723, Tmax = 1.000 | Rint = 0.024 |
5962 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.135 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.51 e Å−3 |
2645 reflections | Δρmin = −0.31 e Å−3 |
110 parameters |
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 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. |
x | y | z | Uiso*/Ueq | ||
Cl2 | 0.00177 (6) | 0.70740 (7) | 0.80205 (4) | 0.0376 (1) | |
N1 | 0.21428 (18) | 0.72294 (18) | 0.52218 (14) | 0.0255 (3) | |
N4 | −0.14312 (18) | 0.76886 (17) | 0.40874 (13) | 0.0247 (3) | |
C2 | 0.0251 (2) | 0.7312 (2) | 0.60775 (15) | 0.0241 (3) | |
C3 | −0.1618 (2) | 0.7568 (2) | 0.55461 (15) | 0.0231 (3) | |
C4A | 0.0544 (2) | 0.7597 (2) | 0.31326 (15) | 0.0235 (3) | |
C5 | 0.0785 (2) | 0.7733 (2) | 0.15555 (16) | 0.0296 (4) | |
C6 | 0.2739 (3) | 0.7667 (3) | 0.05928 (17) | 0.0350 (5) | |
C7 | 0.4533 (3) | 0.7452 (3) | 0.11537 (18) | 0.0352 (4) | |
C8 | 0.4348 (2) | 0.7302 (2) | 0.26786 (18) | 0.0304 (4) | |
C8A | 0.2340 (2) | 0.7380 (2) | 0.36893 (15) | 0.0237 (3) | |
C31 | −0.3786 (2) | 0.7725 (2) | 0.66060 (17) | 0.0281 (4) | |
H5 | −0.04064 | 0.78701 | 0.11676 | 0.0355* | |
H6 | 0.28933 | 0.77665 | −0.04652 | 0.0420* | |
H7 | 0.58771 | 0.74115 | 0.04689 | 0.0422* | |
H8 | 0.55602 | 0.71478 | 0.30513 | 0.0364* | |
H31A | −0.47923 | 0.77223 | 0.60606 | 0.0422* | |
H31B | −0.35850 | 0.65528 | 0.74960 | 0.0422* | |
H31C | −0.43902 | 0.90007 | 0.69508 | 0.0422* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl2 | 0.0392 (2) | 0.0539 (3) | 0.0267 (2) | −0.0194 (2) | −0.0076 (1) | −0.0133 (2) |
N1 | 0.0232 (5) | 0.0307 (6) | 0.0270 (5) | −0.0123 (4) | −0.0069 (4) | −0.0068 (4) |
N4 | 0.0210 (5) | 0.0291 (6) | 0.0268 (5) | −0.0097 (4) | −0.0064 (4) | −0.0074 (4) |
C2 | 0.0248 (6) | 0.0269 (6) | 0.0246 (6) | −0.0102 (5) | −0.0071 (5) | −0.0076 (5) |
C3 | 0.0211 (5) | 0.0230 (6) | 0.0273 (6) | −0.0085 (4) | −0.0062 (4) | −0.0063 (5) |
C4A | 0.0220 (5) | 0.0259 (6) | 0.0246 (6) | −0.0094 (5) | −0.0068 (4) | −0.0053 (5) |
C5 | 0.0297 (6) | 0.0371 (8) | 0.0253 (6) | −0.0131 (6) | −0.0086 (5) | −0.0069 (5) |
C6 | 0.0367 (8) | 0.0445 (9) | 0.0240 (7) | −0.0160 (7) | −0.0042 (5) | −0.0077 (6) |
C7 | 0.0286 (7) | 0.0442 (9) | 0.0308 (7) | −0.0163 (6) | 0.0007 (5) | −0.0077 (6) |
C8 | 0.0229 (6) | 0.0355 (8) | 0.0345 (7) | −0.0132 (5) | −0.0044 (5) | −0.0078 (6) |
C8A | 0.0215 (5) | 0.0263 (6) | 0.0259 (6) | −0.0099 (5) | −0.0068 (4) | −0.0057 (5) |
C31 | 0.0213 (5) | 0.0339 (7) | 0.0298 (7) | −0.0105 (5) | −0.0013 (5) | −0.0107 (5) |
Cl2—C2 | 1.7420 (14) | C6—C7 | 1.415 (3) |
N1—C2 | 1.297 (2) | C7—C8 | 1.373 (2) |
N1—C8A | 1.3782 (18) | C8—C8A | 1.413 (2) |
N4—C3 | 1.3159 (17) | C5—H5 | 0.9500 |
N4—C4A | 1.374 (2) | C6—H6 | 0.9500 |
C2—C3 | 1.436 (2) | C7—H7 | 0.9500 |
C3—C31 | 1.507 (2) | C8—H8 | 0.9500 |
C4A—C5 | 1.4169 (19) | C31—H31A | 0.9800 |
C4A—C8A | 1.414 (2) | C31—H31B | 0.9800 |
C5—C6 | 1.368 (3) | C31—H31C | 0.9800 |
Cl2···C4Ai | 3.6077 (15) | C5···H31Bvi | 2.9300 |
Cl2···H5ii | 3.1100 | C6···H31Bvi | 2.9500 |
Cl2···H6ii | 3.0400 | C7···H31Bvi | 3.0800 |
Cl2···H31B | 2.8700 | C8···H31Ci | 2.8800 |
Cl2···H31C | 3.0800 | C31···H6iii | 3.0000 |
Cl2···H7iii | 3.0500 | H5···Cl2vii | 3.1100 |
N1···N4 | 2.820 (2) | H6···Cl2vii | 3.0400 |
N4···N1 | 2.820 (2) | H6···C31viii | 3.0000 |
N1···H31Aiv | 2.6600 | H7···Cl2viii | 3.0500 |
N4···H8v | 2.7500 | H8···N4iv | 2.7500 |
C3···C4Avi | 3.425 (2) | H31A···N1v | 2.6600 |
C4A···Cl2i | 3.6077 (15) | H31B···Cl2 | 2.8700 |
C4A···C3vi | 3.425 (2) | H31B···C4Avi | 3.0300 |
C4A···C31vi | 3.581 (2) | H31B···C5vi | 2.9300 |
C8A···C31vi | 3.564 (2) | H31B···C6vi | 2.9500 |
C31···C4Avi | 3.581 (2) | H31B···C7vi | 3.0800 |
C31···C8Avi | 3.564 (2) | H31C···Cl2 | 3.0800 |
C4A···H31Bvi | 3.0300 | H31C···C8i | 2.8800 |
C2—N1—C8A | 116.20 (14) | N1—C8A—C8 | 119.77 (14) |
C3—N4—C4A | 118.27 (13) | C4A—C8A—C8 | 120.11 (13) |
Cl2—C2—N1 | 116.17 (12) | C4A—C5—H5 | 120.00 |
Cl2—C2—C3 | 118.67 (11) | C6—C5—H5 | 120.00 |
N1—C2—C3 | 125.16 (13) | C5—C6—H6 | 120.00 |
N4—C3—C2 | 118.88 (13) | C7—C6—H6 | 120.00 |
N4—C3—C31 | 119.21 (14) | C6—C7—H7 | 120.00 |
C2—C3—C31 | 121.91 (12) | C8—C7—H7 | 120.00 |
N4—C4A—C5 | 119.38 (14) | C7—C8—H8 | 120.00 |
N4—C4A—C8A | 121.37 (12) | C8A—C8—H8 | 120.00 |
C5—C4A—C8A | 119.25 (13) | C3—C31—H31A | 109.00 |
C4A—C5—C6 | 119.78 (15) | C3—C31—H31B | 109.00 |
C5—C6—C7 | 120.82 (14) | C3—C31—H31C | 109.00 |
C6—C7—C8 | 120.58 (17) | H31A—C31—H31B | 109.00 |
C7—C8—C8A | 119.46 (16) | H31A—C31—H31C | 109.00 |
N1—C8A—C4A | 120.12 (13) | H31B—C31—H31C | 109.00 |
C8A—N1—C2—Cl2 | 178.86 (10) | N4—C4A—C5—C6 | 179.25 (15) |
C8A—N1—C2—C3 | −0.8 (2) | C8A—C4A—C5—C6 | −0.4 (2) |
C2—N1—C8A—C4A | −0.4 (2) | N4—C4A—C8A—N1 | 0.8 (2) |
C2—N1—C8A—C8 | −179.95 (12) | N4—C4A—C8A—C8 | −179.64 (13) |
C4A—N4—C3—C2 | −1.05 (19) | C5—C4A—C8A—N1 | −179.50 (13) |
C4A—N4—C3—C31 | 178.28 (12) | C5—C4A—C8A—C8 | 0.0 (2) |
C3—N4—C4A—C5 | −179.71 (13) | C4A—C5—C6—C7 | 0.4 (3) |
C3—N4—C4A—C8A | 0.0 (2) | C5—C6—C7—C8 | 0.1 (3) |
Cl2—C2—C3—N4 | −178.05 (11) | C6—C7—C8—C8A | −0.5 (3) |
Cl2—C2—C3—C31 | 2.63 (18) | C7—C8—C8A—N1 | 179.97 (15) |
N1—C2—C3—N4 | 1.6 (2) | C7—C8—C8A—C4A | 0.4 (2) |
N1—C2—C3—C31 | −177.76 (13) |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) x, y, z+1; (iii) x−1, y, z+1; (iv) x+1, y, z; (v) x−1, y, z; (vi) −x, −y+1, −z+1; (vii) x, y, z−1; (viii) x+1, y, z−1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C31—H31B···Cgvi | 0.98 | 2.71 | 3.461 (2) | 133.00 |
Symmetry code: (vi) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C9H7ClN2 |
Mr | 178.62 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 200 |
a, b, c (Å) | 6.8876 (4), 7.4022 (4), 9.4124 (5) |
α, β, γ (°) | 70.654 (4), 72.438 (5), 65.019 (5) |
V (Å3) | 403.01 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.41 |
Crystal size (mm) | 0.51 × 0.49 × 0.22 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini diffractometer |
Absorption correction | Multi-scan (CrysAlis RED; Oxford Diffraction, 2007) |
Tmin, Tmax | 0.723, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5962, 2645, 2094 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.753 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.135, 1.08 |
No. of reflections | 2645 |
No. of parameters | 110 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.51, −0.31 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2007), CrysAlis RED (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
C31—H31B···Cgi | 0.98 | 2.71 | 3.461 (2) | 133.00 |
Symmetry code: (i) −x, −y+1, −z+1. |
Various quinoxaline derivatives have aroused considerable interest of chemistry due to their versatile practical applications as well as their wide range of biological properties. Literature survey reveals that a large number of quinoxaline derivatives have been shown to possess a variety of pharmacological properties like antibacterial, antifungal, antiturberculosis, analgesic and anti-inflammatory activities and hence it is found to be an important structural feature in some synthetic drugs (Craig & Akinpelu, 2005; Michaus & Belen, 2005; and Vyas et al. 2005). Certain quinoxaline derivatives have been reported to possess antiallergic properties. Some natural compounds (echinomicine, triostine) contains quinoxaline skeleton. Thus quinoxaline derivatives continue to attract much attention as potential biological interest.
In the title molecule, C9H7ClN2, (Fig.1), the quinoxaline unit is planar. The benzene ring makes a dihedral angle of 0.48 (7)° with the pyrazine ring. A weak C31—H31B···π interaction involving a methyl hydrogen and the benzene ring is found in the crystal structure and there are no classical hydrogen bonds.