6-Chloro-3-(3-methyl-phen-yl)-1,2,4-triazolo[4,3-b]pyridazine.

The title compound, C(12)H(9)ClN(4), was prepared from dichloro-pyridazine and tolyl-tetra-zole in a nucleophilic biaryl coupling followed by thermal ring transformation. The mol-ecule is essentially planar (r.m.s. deviation for all non-H atoms = 0.036 Å) and an intra-molecular C-H⋯N hydrogen bond occurs. In the crystal, the mol-ecules form dimers connected via π-π inter-actions [centroid-centroid distance = 3.699 (2) Å], which are further connected to neighbouring mol-ecules 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 azines, see: Huisgen 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 azines, see: Preis et al. (2011 ▶).

Experimental

Crystal data

C12H9ClN4

M = 244.68

Monoclinic,

a = 7.1001 (18) Å

b = 11.431 (3) Å

c = 13.783 (3) Å

β = 93.403 (6)°

V = 1116.6 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.32 mm−1

T = 173 K

0.60 × 0.05 × 0.05 mm

Data collection

Bruker SMART APEXII diffractometer

14031 measured reflections

2664 independent reflections

1226 reflections with I > 2σ(I)

R int = 0.130

Refinement

R[F 2 > 2σ(F 2)] = 0.050

wR(F 2) = 0.132

S = 0.84

2664 reflections

155 parameters

H-atom parameters constrained

Δρmax = 0.48 e Å−3

Δρmin = −0.26 e Å−3

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: 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.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811035288/bt5632sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811035288/bt5632Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811035288/bt5632Isup3.cml

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

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	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

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

Table 1

Hydrogen-bond geometry (Å, °)

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) .