organic compounds
6-Chloro-3-(3-methylphenyl)-1,2,4-triazolo[4,3-b]pyridazine
aUniversity Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
*Correspondence e-mail: detert@uni-mainz.de
The title compound, C12H9ClN4, was prepared from dichloropyridazine and tolyltetrazole in a nucleophilic biaryl coupling followed by thermal ring transformation. The molecule is essentially planar (r.m.s. deviation for all non-H atoms = 0.036 Å) and an intramolecular C—H⋯N hydrogen bond occurs. In the crystal, the molecules form dimers connected via π–π interactions [centroid–centroid distance = 3.699 (2) Å], which are further connected to neighbouring molecules via C—H—N bonds. The bond lengths in the pyridazine ring system indicate a strong localization of the double bonds and there is a weak C—Cl bond [1.732 (3) Å].
Related literature
The acylation of tetrazoles with chloroazines and thermal ring transformation leads to triazolo annulated et al. (1961); Glang et al. (2008). For two benzo-annulated triazolopyridazines, see: Boulanger et al. (1991). For a highly phenylated triazolopyrazine, see: Kozhevnikov et al. (2005)·For the synthesis of higher conjugated and annulated heterocyclic π-systems see: Detert & Schollmeyer (1999); Sugiono & Detert (2001). For the synthesis of 1,3,4-oxadiazoles and triazoles, see: Huisgen, Sauer & Seidel (1960); Huisgen, Sturm & Markgraf (1960) and of triazolo-annulated see: Preis et al. (2011).
see: HuisgenExperimental
Crystal data
|
Data collection
|
Refinement
|
Data collection: APEX2 (Bruker, 2006); cell SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supporting information
https://doi.org/10.1107/S1600536811035288/bt5632sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811035288/bt5632Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536811035288/bt5632Isup3.cml
The title compound was prepared by adding pyridine (0.89 g, 10 mmol) to a solution of 3,6-dichloropyridazine (0.45 g, 3 mmol) and 5-(3-methyl- phenyl)tetrazole (0.96 g, 9 mmol) in toluene (15 ml). The mixture was heated to relflux for 5 h, cooled, filtered, and concentrated. The residue was purified by
(SiO2 /toluene/ethyl acetate = 1/1, Rf = 0,23). The title compound was isolated as an off-white powder with m.p. = 422 - 425 K. Crystals were obtained by slow evaporation of a solution of the title compound in chloroform/hexanes.Hydrogen atoms attached to carbons were placed at calculated positions with C—H = 0.95 Å (aromatic) or 0.98–0.99 Å (sp3 C-atom). All H atoms were refined in the riding-model approximation with isotropic displacement parameters set at 1.2–1.5 times of the Ueq of the parent atom.
The title compound was synthesized as part of a larger project focusing on the synthesis of higher conjugated and annulated heterocyclic π-systems (Detert & Schollmeyer, 1999; Sugiono & Detert, 2001). The acylation of tetrazoles followed by thermal ring transformation is a highly efficient route for the synthesis of 1,3,4-oxadiazoles and triazoles (Huisgen, Sauer & Seidel, 1960; Huisgen, Sturm & Markgraf, 1960) and can also be applied to 2-chloroazines to yield triazolo-annulated (Preis et al., 2011). In the crystal the title compound adopts an essentially planar structure with a dihedral angle of 2.21° between the mean planes of the phenyl ring and the bicyclic system and deviations of less than 0.01 Å from the least square plane. All torsion angles in the C—N-framework are below 2°; the torsion angle of -176.5 (3)° (C16—C12—C13—C14) results from methyl substitution. With 1.372 (3)Å (N2—N3) and 1.381 (3)Å (N8 - N9), the N—N bonds in the bicyclic framework are significantly longer than the C—N bonds C1—N2 (1.290 (4) Å), C4 - N9 (1.317 (4) Å), and C7 - N8 (1.324 (4) Å). This, the longer bonds N3—C4 (1.383 (4) Å) and N3 - C7 (1.378 (4) Å) and the alternating C—C bond lengths in the pyridazine (C4 - C5: 1.416 (4) Å; C5 - C6: 1.3435 (4) Å; C1 - C6: 1.426 (4) Å) indicate a strong localization of the double bonds. Contrary to the short bond C1 - N2 (1.290 (4) Å), the C1 - Cl1 bond (1.732 (3) Å) is long. This correlates with the reactivity of the C1—Cl1 bond, similar to an imidoyl chloride. Two molecules are connected via a center of inversion (symmetry operator: 1-x, 1-y, 1-z), by π-π-interactions and hydrogen bridging stabilize the lattice. The distances of the centroids of pyridazine and tolyl rings are only 3.70 Å and C—H—N bonds between C6—H6—N9 (H6—N9: 2.55 Å) connect the molecules.
The acylation of tetrazoles with chloroazines and thermal ring transformation leads to triazolo annulated π-systems see: Detert & Schollmeyer (1999); Sugiono & Detert (2001). For the synthesis of 1,3,4-oxadiazoles and triazoles, see: Huisgen, Sauer & Seidel (1960); Huisgen, Sturm & Markgraf (1960) and of triazolo-annulated see: Preis et al. (2011).
see: Huisgen et al. (1961); Glang et al. (2008). For two benzo-annulated [compounds?], see: Boulanger et al. (1991). For a highly phenylated triazolopyrazine, see: Kozhevnikov et al. (2005).For the synthesis of higher conjugated and annulated heterocyclicData collection: APEX2 (Bruker, 2006); cell
SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).Fig. 1. View of compound I. Displacement ellipsoids are drawn at the 50% probability level. |
C12H9ClN4 | F(000) = 504 |
Mr = 244.68 | Dx = 1.456 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2ybc | Cell parameters from 1195 reflections |
a = 7.1001 (18) Å | θ = 2.3–20.2° |
b = 11.431 (3) Å | µ = 0.32 mm−1 |
c = 13.783 (3) Å | T = 173 K |
β = 93.403 (6)° | Needle, colourless |
V = 1116.6 (5) Å3 | 0.60 × 0.05 × 0.05 mm |
Z = 4 |
Bruker SMART APEXII diffractometer | 1226 reflections with I > 2σ(I) |
Radiation source: sealed Tube | Rint = 0.130 |
Graphite monochromator | θmax = 27.9°, θmin = 2.3° |
CCD scan | h = −9→9 |
14031 measured reflections | k = −15→14 |
2664 independent reflections | l = −18→18 |
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)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 0.84 | w = 1/[σ2(Fo2) + (0.056P)2] where P = (Fo2 + 2Fc2)/3 |
2664 reflections | (Δ/σ)max < 0.001 |
155 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
C12H9ClN4 | V = 1116.6 (5) Å3 |
Mr = 244.68 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.1001 (18) Å | µ = 0.32 mm−1 |
b = 11.431 (3) Å | T = 173 K |
c = 13.783 (3) Å | 0.60 × 0.05 × 0.05 mm |
β = 93.403 (6)° |
Bruker SMART APEXII diffractometer | 1226 reflections with I > 2σ(I) |
14031 measured reflections | Rint = 0.130 |
2664 independent reflections |
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 0.84 | Δρmax = 0.48 e Å−3 |
2664 reflections | Δρmin = −0.26 e Å−3 |
155 parameters |
Experimental. 1H-NMR (300 MHz,CDCl3): 8.23 (m, 2 H, 2-H, 6-H, ph), 8.16 (d, 1 H, J = 9.6 Hz, 5-H pyr), 7.41 (t, 1 H, 5-H, ph), 7.32 (d, J = 8.2 Hz, 1 H. 4-H, ph), 7.13 (d, 1 H, J = 9.6 Hz, 4-H pyr), 2.52 (s, 3 H, CH3). 13C-NMR (75 MHz,CDCl3): 149.1 (Cq), 148.2 (Cq), 143.5 (Cq), 139.0 (Cq), 136.6 (Cq), 131.6 (CH), 128.7 (CH), 128.3 (CH), 126.6 (CH), 124.7 (CH), 122.0 (CH), 21.5 (CH3). FD-MS: 244.3 (M++, 100%, Cl-pattern). |
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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.14497 (13) | 0.12426 (7) | 0.55906 (6) | 0.0543 (3) | |
C1 | 0.1347 (4) | 0.2284 (3) | 0.4676 (2) | 0.0351 (7) | |
N2 | 0.1881 (3) | 0.3314 (2) | 0.49595 (17) | 0.0319 (6) | |
N3 | 0.1769 (3) | 0.41168 (19) | 0.42183 (16) | 0.0300 (6) | |
C4 | 0.1166 (4) | 0.3900 (3) | 0.3262 (2) | 0.0346 (7) | |
C5 | 0.0608 (4) | 0.2744 (3) | 0.3013 (2) | 0.0374 (7) | |
H5 | 0.0189 | 0.2548 | 0.2366 | 0.045* | |
C6 | 0.0691 (4) | 0.1934 (3) | 0.3722 (2) | 0.0373 (7) | |
H6 | 0.0321 | 0.1148 | 0.3590 | 0.045* | |
C7 | 0.2199 (4) | 0.5292 (2) | 0.4268 (2) | 0.0349 (7) | |
N8 | 0.1856 (4) | 0.5739 (2) | 0.3389 (2) | 0.0432 (7) | |
N9 | 0.1210 (4) | 0.4874 (2) | 0.27542 (18) | 0.0432 (7) | |
C10 | 0.2901 (4) | 0.5958 (2) | 0.5118 (2) | 0.0377 (7) | |
C11 | 0.3162 (4) | 0.5480 (3) | 0.6046 (2) | 0.0416 (8) | |
H11 | 0.2890 | 0.4676 | 0.6143 | 0.050* | |
C12 | 0.3820 (4) | 0.6163 (3) | 0.6838 (3) | 0.0462 (8) | |
C13 | 0.4225 (4) | 0.7318 (3) | 0.6691 (3) | 0.0534 (10) | |
H13 | 0.4694 | 0.7782 | 0.7224 | 0.064* | |
C14 | 0.3961 (5) | 0.7824 (3) | 0.5778 (3) | 0.0576 (11) | |
H14 | 0.4227 | 0.8630 | 0.5690 | 0.069* | |
C15 | 0.3300 (4) | 0.7138 (3) | 0.4989 (3) | 0.0493 (9) | |
H15 | 0.3123 | 0.7479 | 0.4362 | 0.059* | |
C16 | 0.4006 (6) | 0.5656 (3) | 0.7827 (3) | 0.0736 (12) | |
H16A | 0.4618 | 0.4889 | 0.7802 | 0.110* | |
H16B | 0.2752 | 0.5566 | 0.8079 | 0.110* | |
H16C | 0.4771 | 0.6176 | 0.8256 | 0.110* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0708 (6) | 0.0485 (5) | 0.0425 (5) | −0.0143 (4) | −0.0053 (4) | 0.0108 (4) |
C1 | 0.0308 (16) | 0.0411 (18) | 0.0331 (19) | −0.0015 (13) | −0.0003 (14) | 0.0048 (13) |
N2 | 0.0285 (13) | 0.0389 (14) | 0.0279 (14) | −0.0026 (11) | −0.0009 (11) | 0.0018 (10) |
N3 | 0.0262 (13) | 0.0361 (14) | 0.0274 (14) | −0.0001 (10) | −0.0003 (10) | −0.0025 (10) |
C4 | 0.0278 (15) | 0.0449 (18) | 0.0308 (17) | 0.0044 (13) | 0.0007 (13) | −0.0017 (14) |
C5 | 0.0328 (17) | 0.0533 (19) | 0.0254 (17) | −0.0003 (14) | −0.0048 (14) | −0.0088 (14) |
C6 | 0.0326 (17) | 0.0400 (18) | 0.039 (2) | −0.0066 (13) | −0.0005 (14) | −0.0060 (14) |
C7 | 0.0285 (16) | 0.0368 (17) | 0.0395 (19) | 0.0028 (13) | 0.0039 (14) | −0.0014 (13) |
N8 | 0.0455 (16) | 0.0393 (15) | 0.0446 (17) | 0.0024 (12) | 0.0010 (13) | 0.0038 (13) |
N9 | 0.0479 (16) | 0.0456 (16) | 0.0356 (16) | 0.0028 (13) | −0.0004 (13) | 0.0048 (12) |
C10 | 0.0263 (16) | 0.0366 (18) | 0.051 (2) | −0.0002 (13) | 0.0081 (14) | −0.0097 (14) |
C11 | 0.0310 (17) | 0.0449 (19) | 0.049 (2) | −0.0027 (14) | 0.0000 (15) | −0.0131 (15) |
C12 | 0.0322 (17) | 0.056 (2) | 0.051 (2) | −0.0002 (16) | 0.0019 (15) | −0.0142 (17) |
C13 | 0.0346 (19) | 0.060 (2) | 0.066 (3) | −0.0061 (16) | 0.0072 (18) | −0.024 (2) |
C14 | 0.039 (2) | 0.044 (2) | 0.090 (3) | −0.0096 (16) | 0.013 (2) | −0.018 (2) |
C15 | 0.0389 (19) | 0.045 (2) | 0.064 (3) | 0.0013 (15) | 0.0091 (18) | −0.0033 (17) |
C16 | 0.073 (3) | 0.080 (3) | 0.065 (3) | 0.004 (2) | −0.012 (2) | −0.018 (2) |
Cl1—C1 | 1.732 (3) | C10—C15 | 1.392 (4) |
C1—N2 | 1.290 (4) | C10—C11 | 1.393 (4) |
C1—C6 | 1.426 (4) | C11—C12 | 1.399 (4) |
N2—N3 | 1.372 (3) | C11—H11 | 0.9500 |
N3—C7 | 1.378 (4) | C12—C13 | 1.369 (5) |
N3—C4 | 1.383 (4) | C12—C16 | 1.481 (5) |
C4—N9 | 1.317 (4) | C13—C14 | 1.387 (5) |
C4—C5 | 1.416 (4) | C13—H13 | 0.9500 |
C5—C6 | 1.345 (4) | C14—C15 | 1.399 (5) |
C5—H5 | 0.9500 | C14—H14 | 0.9500 |
C6—H6 | 0.9500 | C15—H15 | 0.9500 |
C7—N8 | 1.324 (4) | C16—H16A | 0.9800 |
C7—C10 | 1.460 (4) | C16—H16B | 0.9800 |
N8—N9 | 1.381 (3) | C16—H16C | 0.9800 |
N2—C1—C6 | 127.5 (3) | C11—C10—C7 | 123.5 (3) |
N2—C1—Cl1 | 114.0 (2) | C10—C11—C12 | 121.1 (3) |
C6—C1—Cl1 | 118.4 (2) | C10—C11—H11 | 119.4 |
C1—N2—N3 | 112.4 (2) | C12—C11—H11 | 119.4 |
N2—N3—C7 | 127.7 (2) | C13—C12—C11 | 119.1 (3) |
N2—N3—C4 | 126.2 (2) | C13—C12—C16 | 120.4 (3) |
C7—N3—C4 | 106.1 (2) | C11—C12—C16 | 120.5 (3) |
N9—C4—N3 | 109.8 (2) | C12—C13—C14 | 121.1 (3) |
N9—C4—C5 | 132.4 (3) | C12—C13—H13 | 119.4 |
N3—C4—C5 | 117.7 (3) | C14—C13—H13 | 119.4 |
C6—C5—C4 | 117.8 (3) | C13—C14—C15 | 119.5 (3) |
C6—C5—H5 | 121.1 | C13—C14—H14 | 120.2 |
C4—C5—H5 | 121.1 | C15—C14—H14 | 120.2 |
C5—C6—C1 | 118.3 (3) | C10—C15—C14 | 120.3 (4) |
C5—C6—H6 | 120.8 | C10—C15—H15 | 119.8 |
C1—C6—H6 | 120.8 | C14—C15—H15 | 119.8 |
N8—C7—N3 | 107.6 (3) | C12—C16—H16A | 109.5 |
N8—C7—C10 | 124.6 (3) | C12—C16—H16B | 109.5 |
N3—C7—C10 | 127.8 (3) | H16A—C16—H16B | 109.5 |
C7—N8—N9 | 109.8 (2) | C12—C16—H16C | 109.5 |
C4—N9—N8 | 106.6 (2) | H16A—C16—H16C | 109.5 |
C15—C10—C11 | 118.7 (3) | H16B—C16—H16C | 109.5 |
C15—C10—C7 | 117.7 (3) | ||
C6—C1—N2—N3 | −0.1 (4) | C10—C7—N8—N9 | 179.9 (3) |
Cl1—C1—N2—N3 | −179.59 (18) | N3—C4—N9—N8 | 0.1 (3) |
C1—N2—N3—C7 | 179.0 (3) | C5—C4—N9—N8 | 178.9 (3) |
C1—N2—N3—C4 | −0.1 (4) | C7—N8—N9—C4 | 0.1 (3) |
N2—N3—C4—N9 | 178.9 (2) | N8—C7—C10—C15 | −2.3 (4) |
C7—N3—C4—N9 | −0.3 (3) | N3—C7—C10—C15 | 177.9 (3) |
N2—N3—C4—C5 | −0.0 (4) | N8—C7—C10—C11 | 176.7 (3) |
C7—N3—C4—C5 | −179.3 (2) | N3—C7—C10—C11 | −3.1 (5) |
N9—C4—C5—C6 | −178.4 (3) | C15—C10—C11—C12 | −0.2 (4) |
N3—C4—C5—C6 | 0.3 (4) | C7—C10—C11—C12 | −179.2 (3) |
C4—C5—C6—C1 | −0.5 (4) | C10—C11—C12—C13 | −0.5 (4) |
N2—C1—C6—C5 | 0.4 (5) | C10—C11—C12—C16 | 177.2 (3) |
Cl1—C1—C6—C5 | 179.9 (2) | C11—C12—C13—C14 | 1.2 (5) |
N2—N3—C7—N8 | −178.9 (2) | C16—C12—C13—C14 | −176.5 (3) |
C4—N3—C7—N8 | 0.3 (3) | C12—C13—C14—C15 | −1.1 (5) |
N2—N3—C7—C10 | 1.0 (4) | C11—C10—C15—C14 | 0.4 (4) |
C4—N3—C7—C10 | −179.9 (3) | C7—C10—C15—C14 | 179.4 (3) |
N3—C7—N8—N9 | −0.3 (3) | C13—C14—C15—C10 | 0.3 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···N9i | 0.95 | 2.55 | 3.344 (4) | 141 |
C11—H11···N2 | 0.95 | 2.34 | 3.006 (4) | 127 |
C15—H15···N8 | 0.95 | 2.53 | 2.864 (5) | 101 |
Symmetry code: (i) −x, y−1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C12H9ClN4 |
Mr | 244.68 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 7.1001 (18), 11.431 (3), 13.783 (3) |
β (°) | 93.403 (6) |
V (Å3) | 1116.6 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.32 |
Crystal size (mm) | 0.60 × 0.05 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEXII |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14031, 2664, 1226 |
Rint | 0.130 |
(sin θ/λ)max (Å−1) | 0.658 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.050, 0.132, 0.84 |
No. of reflections | 2664 |
No. of parameters | 155 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.48, −0.26 |
Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···N9i | 0.95 | 2.55 | 3.344 (4) | 141 |
C11—H11···N2 | 0.95 | 2.34 | 3.006 (4) | 127 |
Symmetry code: (i) −x, y−1/2, −z+1/2. |
Acknowledgements
The authors are grateful to Heinz Kolshorn for the NMR spectra and invaluable discussions.
References
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Boulanger, T., Evrard, C., Vercauteren, D. P., Evrard, G. & Durant, F. (1991). J. Crystallogr. Spectrosc. Res. 21, 287–295. CSD CrossRef CAS Web of Science Google Scholar
Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Detert, H. & Schollmeyer, D. (1999). Synthesis, pp. 999–1004. CSD CrossRef Google Scholar
Glang, S., Schmitt, V. & Detert, H. (2008). Proc. 36th Ger. Top. Meet. Liq. Cryst. pp. 125–128. Google Scholar
Huisgen, R., Sauer, J. & Seidel, M. (1960). Chem. Ber. 93, 2885–2891. CrossRef CAS Web of Science Google Scholar
Huisgen, R., Sturm, H. J. & Markgraf, J. H. (1960). Chem. Ber. 93, 2106–2124. CrossRef CAS Web of Science Google Scholar
Huisgen, R., Sturm, H. J. & Seidel, M. (1961). Chem. Ber. 94, 1555–1562. CrossRef CAS Web of Science Google Scholar
Kozhevnikov, D. N., Kataeva, N. N. & Rusinov, V. L. (2005). Mendeleev. Commun. p. 31. CrossRef Google Scholar
Preis, J., Schollmeyer, D. & Detert, H. (2011). Acta Cryst. E67, o987. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sugiono, E. & Detert, H. (2001). Synthesis, pp. 893–896. CrossRef Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title compound was synthesized as part of a larger project focusing on the synthesis of higher conjugated and annulated heterocyclic π-systems (Detert & Schollmeyer, 1999; Sugiono & Detert, 2001). The acylation of tetrazoles followed by thermal ring transformation is a highly efficient route for the synthesis of 1,3,4-oxadiazoles and triazoles (Huisgen, Sauer & Seidel, 1960; Huisgen, Sturm & Markgraf, 1960) and can also be applied to 2-chloroazines to yield triazolo-annulated azines (Preis et al., 2011). In the crystal the title compound adopts an essentially planar structure with a dihedral angle of 2.21° between the mean planes of the phenyl ring and the bicyclic system and deviations of less than 0.01 Å from the least square plane. All torsion angles in the C—N-framework are below 2°; the torsion angle of -176.5 (3)° (C16—C12—C13—C14) results from methyl substitution. With 1.372 (3)Å (N2—N3) and 1.381 (3)Å (N8 - N9), the N—N bonds in the bicyclic framework are significantly longer than the C—N bonds C1—N2 (1.290 (4) Å), C4 - N9 (1.317 (4) Å), and C7 - N8 (1.324 (4) Å). This, the longer bonds N3—C4 (1.383 (4) Å) and N3 - C7 (1.378 (4) Å) and the alternating C—C bond lengths in the pyridazine (C4 - C5: 1.416 (4) Å; C5 - C6: 1.3435 (4) Å; C1 - C6: 1.426 (4) Å) indicate a strong localization of the double bonds. Contrary to the short bond C1 - N2 (1.290 (4) Å), the C1 - Cl1 bond (1.732 (3) Å) is long. This correlates with the reactivity of the C1—Cl1 bond, similar to an imidoyl chloride. Two molecules are connected via a center of inversion (symmetry operator: 1-x, 1-y, 1-z), by π-π-interactions and hydrogen bridging stabilize the lattice. The distances of the centroids of pyridazine and tolyl rings are only 3.70 Å and C—H—N bonds between C6—H6—N9 (H6—N9: 2.55 Å) connect the molecules.