2,7-Dimethyl-1,3-thia­zolo[4,5-d]pyridazin-4(5H)-one

Abstract

The nine-membered fused-ring system of the title pyridazine derivative, C₇H₇N₃OS, is almost planar (r.m.s. deviation 0.012 Å). In the crystal, the amino H atom forms a hydrogen bond to the ketonic O atom of a neighboring mol­ecule to generate a centrosymmetric dimer.

Related literature

For a related structure, see: Abdel-Aziz et al. (2010 ▶). For the biological activity of the class of pyridazines, see: Faid-Allah et al. (2011 ▶); Makki & Faid-Allah (1996 ▶).

Experimental

Crystal data

• C₇H₇N₃OS

• M _r = 181.22

• Triclinic,

• a = 6.9262 (4) Å

• b = 7.0540 (4) Å

• c = 8.8079 (6) Å

• α = 71.002 (6)°

• β = 75.845 (5)°

• γ = 85.570 (5)°

• V = 394.54 (4) ų

• Z = 2

• Cu Kα radiation

• μ = 3.26 mm⁻¹

• T = 100 K

• 0.30 × 0.25 × 0.20 mm

Data collection

• Agilent Technologies SuperNova Dual diffractometer with Atlas detector

• Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.442, T _max = 0.562

• 2363 measured reflections

• 1539 independent reflections

• 1523 reflections with I > 2σ(I)

• R _int = 0.012

Refinement

• R[F ² > 2σ(F ²)] = 0.029

• wR(F ²) = 0.080

• S = 1.05

• 1539 reflections

• 115 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.41 e Å⁻³

• Δρ_min = −0.30 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811034192/xu5288Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O1i	0.88 (2)	1.97 (2)	2.845 (2)	173 (2)

Symmetry code: (i) .

supplementary crystallographic information

Comment

We have reported the synthesis of some pyridazines, which exhibit biological activity (Faid-Allah et al., 2011; Makki & Faid-Allah, 1996). There are few crystal structure reports of such systems; recently, we reported the crystal structure of 3-methyl-2-(4-methyl)-2H-pyrazolo[3,4-d]pyridazin-5-ium thiocyanate, a salt (Abdel-Aziz et al., 2010). The nine-membered fused-ring system of C₇H₇N₃OS (Scheme I) is planar (Fig. 1). The amino group forms a hydrogen bond to the ketonic O atom of a neigboring molecule to form a dimer (Table 1).

Experimental

A solution of ethyl 5-acetyl-3-methylisoxazole-4-carboxylate (2.10 g, 10 mmol) in ethanol (25 ml) was refluxed with hydrazine hydrate (0.50 g, 10 mmol) for 2 h. The pyridazine which separated after concentration of the reaction mixture was filtered off, washed with ethanol and recrystallized from the same solvent to give colorless prisms in 90% yield, mp 527 K.

Refinement

Carbon-bound H-atoms were placed in calculated positions [C—H 0.95 to 0.98 Å, U_iso(H) 1.2 to 1.5U_eq(C)] and were included in the refinement in the riding model approximation.

The amino H-atom was located in a difference Fourier map, and were refined freely.

Omitted were (4 0 4), (1 0 1) and (-7 - 2 1).

Figures

Fig. 1.

Thermal ellipsoid plot (Barbour, 2001) of C7H7N3OS at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

Crystal data

C7H7N3OS	Z = 2
Mr = 181.22	F(000) = 188
Triclinic, P1	Dx = 1.525 Mg m−3
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54184 Å
a = 6.9262 (4) Å	Cell parameters from 1965 reflections
b = 7.0540 (4) Å	θ = 6.6–74.2°
c = 8.8079 (6) Å	µ = 3.26 mm−1
α = 71.002 (6)°	T = 100 K
β = 75.845 (5)°	Prism, colorless
γ = 85.570 (5)°	0.30 × 0.25 × 0.20 mm
V = 394.54 (4) Å3

Data collection

Agilent Technologies SuperNova Dual diffractometer with Atlas detector	1539 independent reflections
Radiation source: SuperNova (Cu) X-ray Source	1523 reflections with I > 2σ(I)
Mirror	Rint = 0.012
Detector resolution: 10.4041 pixels mm-1	θmax = 74.4°, θmin = 6.6°
ω scan	h = −8→7
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	k = −8→4
Tmin = 0.442, Tmax = 0.562	l = −10→10
2363 measured reflections

Refinement

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.080	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ2(Fo2) + (0.0494P)2 + 0.260P] where P = (Fo2 + 2Fc2)/3
1539 reflections	(Δ/σ)max = 0.001
115 parameters	Δρmax = 0.41 e Å−3
0 restraints	Δρmin = −0.30 e Å−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	1.29210 (5)	0.13257 (5)	0.50269 (4)	0.01037 (14)
O1	0.59921 (15)	0.34439 (15)	0.67118 (13)	0.0136 (2)
N1	0.97795 (18)	0.13725 (17)	0.73210 (15)	0.0114 (3)
N2	0.74300 (18)	0.42456 (18)	0.39677 (15)	0.0112 (3)
H2	0.636 (3)	0.490 (3)	0.371 (3)	0.027 (5)*
N3	0.88967 (18)	0.43408 (18)	0.25907 (15)	0.0121 (3)
C1	1.2623 (2)	−0.0391 (2)	0.84407 (19)	0.0157 (3)
H1A	1.1669	−0.0660	0.9512	0.024*
H1B	1.3732	0.0410	0.8415	0.024*
H1C	1.3131	−0.1663	0.8277	0.024*
C2	1.1611 (2)	0.0736 (2)	0.70979 (18)	0.0118 (3)
C3	0.9338 (2)	0.2388 (2)	0.58191 (17)	0.0103 (3)
C4	0.7459 (2)	0.3356 (2)	0.56003 (18)	0.0107 (3)
C5	1.0839 (2)	0.2502 (2)	0.44375 (18)	0.0101 (3)
C6	1.0596 (2)	0.3495 (2)	0.27985 (18)	0.0111 (3)
C7	1.2245 (2)	0.3608 (2)	0.13145 (18)	0.0167 (3)
H7A	1.1756	0.4244	0.0312	0.025*
H7B	1.2713	0.2252	0.1345	0.025*
H7C	1.3346	0.4401	0.1314	0.025*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0081 (2)	0.0092 (2)	0.0123 (2)	0.00189 (13)	−0.00196 (13)	−0.00205 (14)
O1	0.0089 (5)	0.0137 (5)	0.0156 (5)	0.0007 (4)	0.0001 (4)	−0.0034 (4)
N1	0.0113 (6)	0.0082 (6)	0.0136 (6)	−0.0004 (4)	−0.0028 (5)	−0.0019 (5)
N2	0.0081 (6)	0.0104 (6)	0.0140 (6)	0.0020 (5)	−0.0022 (5)	−0.0032 (5)
N3	0.0120 (6)	0.0103 (6)	0.0130 (6)	0.0000 (5)	−0.0018 (5)	−0.0029 (5)
C1	0.0147 (7)	0.0150 (7)	0.0155 (7)	0.0025 (6)	−0.0051 (6)	−0.0015 (6)
C2	0.0124 (7)	0.0076 (6)	0.0142 (7)	−0.0016 (5)	−0.0020 (5)	−0.0021 (5)
C3	0.0103 (7)	0.0057 (6)	0.0137 (7)	−0.0016 (5)	−0.0019 (5)	−0.0016 (5)
C4	0.0103 (7)	0.0057 (6)	0.0157 (7)	−0.0021 (5)	−0.0030 (5)	−0.0025 (5)
C5	0.0095 (6)	0.0060 (6)	0.0151 (7)	0.0002 (5)	−0.0034 (5)	−0.0034 (5)
C6	0.0122 (7)	0.0078 (6)	0.0127 (7)	−0.0011 (5)	−0.0026 (5)	−0.0022 (5)
C7	0.0151 (7)	0.0191 (8)	0.0127 (7)	0.0022 (6)	−0.0017 (6)	−0.0022 (6)

Geometric parameters (Å, °)

S1—C5	1.7141 (14)	C1—H1A	0.9800
S1—C2	1.7546 (15)	C1—H1B	0.9800
O1—C4	1.2404 (18)	C1—H1C	0.9800
N1—C2	1.3025 (19)	C3—C5	1.378 (2)
N1—C3	1.3797 (18)	C3—C4	1.4480 (19)
N2—N3	1.3647 (17)	C5—C6	1.430 (2)
N2—C4	1.3736 (19)	C6—C7	1.4953 (19)
N2—H2	0.88 (2)	C7—H7A	0.9800
N3—C6	1.3037 (19)	C7—H7B	0.9800
C1—C2	1.493 (2)	C7—H7C	0.9800
C5—S1—C2	89.25 (7)	N1—C3—C4	125.15 (13)
C2—N1—C3	110.07 (12)	O1—C4—N2	120.86 (13)
N3—N2—C4	129.17 (12)	O1—C4—C3	126.43 (13)
N3—N2—H2	111.4 (14)	N2—C4—C3	112.70 (12)
C4—N2—H2	119.3 (14)	C3—C5—C6	122.57 (13)
C6—N3—N2	117.76 (12)	C3—C5—S1	109.49 (11)
C2—C1—H1A	109.5	C6—C5—S1	127.94 (11)
C2—C1—H1B	109.5	N3—C6—C5	119.21 (13)
H1A—C1—H1B	109.5	N3—C6—C7	119.01 (13)
C2—C1—H1C	109.5	C5—C6—C7	121.77 (13)
H1A—C1—H1C	109.5	C6—C7—H7A	109.5
H1B—C1—H1C	109.5	C6—C7—H7B	109.5
N1—C2—C1	125.25 (13)	H7A—C7—H7B	109.5
N1—C2—S1	114.91 (11)	C6—C7—H7C	109.5
C1—C2—S1	119.83 (11)	H7A—C7—H7C	109.5
C5—C3—N1	116.28 (12)	H7B—C7—H7C	109.5
C5—C3—C4	118.56 (13)
C4—N2—N3—C6	−0.4 (2)	N1—C3—C5—C6	179.58 (12)
C3—N1—C2—C1	178.83 (13)	C4—C3—C5—C6	−1.6 (2)
C3—N1—C2—S1	−0.33 (15)	N1—C3—C5—S1	−0.99 (16)
C5—S1—C2—N1	−0.18 (11)	C4—C3—C5—S1	177.81 (10)
C5—S1—C2—C1	−179.39 (12)	C2—S1—C5—C3	0.63 (10)
C2—N1—C3—C5	0.86 (17)	C2—S1—C5—C6	−179.99 (13)
C2—N1—C3—C4	−177.85 (12)	N2—N3—C6—C5	0.55 (19)
N3—N2—C4—O1	178.56 (12)	N2—N3—C6—C7	−178.84 (12)
N3—N2—C4—C3	−0.7 (2)	C3—C5—C6—N3	0.5 (2)
C5—C3—C4—O1	−177.59 (13)	S1—C5—C6—N3	−178.85 (10)
N1—C3—C4—O1	1.1 (2)	C3—C5—C6—C7	179.84 (13)
C5—C3—C4—N2	1.63 (18)	S1—C5—C6—C7	0.5 (2)
N1—C3—C4—N2	−179.69 (12)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1i	0.88 (2)	1.97 (2)	2.845 (2)	173 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1.