8-Bromo-3,4-dihydro-2H-1,3-thia­zino[2,3:2′,1′]imidazo[5′,4′-b]pyridine

Abstract

The imidazopyridine ring system in the title compound, C₉H₈BrN₃S, is almost planar [r.m.s. deviation of the C and N atoms = 0.007 (1) Å]. The S and methyl­ene C atoms connected to the five-membered ring lie within this plane. The remaining two methyl­ene groups of the thia­zine ring are disordered over two sets of sites in a 0.817 (5):0.183 (5) ratio.

Related literature

The parent triclyclic condensed imidazole (without bromine) has been patented as a pharmaceutical; see: Hideg et al. (1975 ▶, 1976 ▶). For other compounds synthesized from 6-bromo-1H-imidazo[4,5-b]pyridine-2(3H)-thione, see: Liszkiewicz et al. (2007 ▶); Prasad et al. (1986 ▶); Yutilov & Svertilova (1988 ▶).

Experimental

Crystal data

• C₉H₈BrN₃S

• M _r = 270.15

• Monoclinic,

• a = 20.2738 (3) Å

• b = 13.2786 (2) Å

• c = 7.3169 (1) Å

• β = 102.193 (1)°

• V = 1925.33 (5) ų

• Z = 8

• Mo Kα radiation

• μ = 4.45 mm⁻¹

• T = 100 K

• 0.46 × 0.14 × 0.12 mm

Data collection

• Bruker X8 APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.234, T _max = 0.618

• 30460 measured reflections

• 3561 independent reflections

• 3003 reflections with I > 2σ(I)

• R _int = 0.039

• Standard reflections: 0

Refinement

• R[F ² > 2σ(F ²)] = 0.024

• wR(F ²) = 0.064

• S = 0.99

• 3561 reflections

• 146 parameters

• 14 restraints

• H-atom parameters constrained

• Δρ_max = 0.49 e Å⁻³

• Δρ_min = −0.55 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; 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

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

supplementary crystallographic information

Comment

Commerically-available 6-bromo-1H-imidazo[4,5-b]pyridine-2(3H)-thione has been used to react with a range of organic compounds to furnish chemicals having useful biological activities (Liszkiewicz et al., 2007; Prasad et al., 1986; Yutilov & Svertilova, 1988). The compound reacts with 1-chloropropanal under catalytic conditions to yield the title triclyclic condensed imidazole (Scheme I, Fig. 1). The imidazopyridine fused ring is planar. One ethylene fragment of the six-membered ring is twisted such that one atom lies above and the other below the plane. This fragment is disordered over two positions.

Experimental

6-Bromo-1H-imidazo[4,5-b]pyridine-2(3H)-thione (1 mmol), potassium carbonate (4 mmol), tetra-n-butylammonium bromide (0.1 mmol) and 1-chloro-propanol (1.5 mmol) in DMF (15 ml) were stirred for 72 h. After completion of reaction (as monitored by TLC), the salt was filtered and the solvent removed under reduced pressure. The resulting residue was purified by column chromatography on silica gel using chloroform/hexane (1/1) as eluent. Colorless crystals were isolated when the solvent was allowed to evaporate.

Refinement

H atoms were placed in calculated positions (C—H = 0.95–0.99 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U(C).

The two methylene atoms next to the S atom are disordered over two sites; the disorder refined to an 0.817 (5):0.183 (5) ratio. The pair of S—C distances were restrained to be equal within 0.01 Å of each other, as were the pair of C—C distances. The anisotropic temperature factors of the primed atoms were restrained to be nearly isotropic.

Figures

Fig. 1.

Anisotropic displacement ellipsoid plot (Barbour, 2001) of C9H8BrN3O at the 70% probability level; H atoms are drawn as spheres of an arbitrary radius. The disorder is not shown.

Crystal data

C9H8BrN3S	F(000) = 1072
Mr = 270.15	Dx = 1.864 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 9070 reflections
a = 20.2738 (3) Å	θ = 2.8–32.5°
b = 13.2786 (2) Å	µ = 4.45 mm−1
c = 7.3169 (1) Å	T = 100 K
β = 102.193 (1)°	Block, colourless
V = 1925.33 (5) Å3	0.46 × 0.14 × 0.12 mm
Z = 8

Data collection

Bruker X8 APEXII diffractometer	3561 independent reflections
Radiation source: fine-focus sealed tube	3003 reflections with I > 2σ(I)
graphite	Rint = 0.039
φ and ω scans	θmax = 32.8°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −30→30
Tmin = 0.234, Tmax = 0.618	k = −20→20
30460 measured reflections	l = −11→11

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)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.064	H-atom parameters constrained
S = 0.99	w = 1/[σ2(Fo2) + (0.0351P)2 + 1.6536P] where P = (Fo2 + 2Fc2)/3
3561 reflections	(Δ/σ)max = 0.001
146 parameters	Δρmax = 0.49 e Å−3
14 restraints	Δρmin = −0.55 e Å−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.446434 (7)	0.655625 (11)	0.45346 (2)	0.02338 (5)
S1	0.082325 (17)	0.50817 (3)	0.60465 (5)	0.01612 (7)
N1	0.20317 (6)	0.43515 (8)	0.54957 (17)	0.0139 (2)
N2	0.19469 (6)	0.60483 (9)	0.56459 (18)	0.0162 (2)
N3	0.31734 (6)	0.42166 (9)	0.50005 (18)	0.0167 (2)
C1	0.07654 (9)	0.37320 (13)	0.6425 (4)	0.0175 (4)	0.817 (5)
H1A	0.0993	0.3568	0.7726	0.021*	0.817 (5)
H1B	0.0285	0.3537	0.6256	0.021*	0.817 (5)
C2	0.10897 (9)	0.31333 (13)	0.5076 (3)	0.0178 (4)	0.817 (5)
H2A	0.0888	0.3342	0.3780	0.021*	0.817 (5)
H2B	0.0991	0.2409	0.5196	0.021*	0.817 (5)
C1'	0.0642 (4)	0.3746 (5)	0.5409 (16)	0.0186 (18)	0.183 (5)
H1'A	0.0233	0.3527	0.5836	0.022*	0.183 (5)
H1'B	0.0556	0.3670	0.4033	0.022*	0.183 (5)
C2'	0.1237 (3)	0.3089 (6)	0.6309 (11)	0.0158 (18)	0.183 (5)
H2'A	0.1106	0.2371	0.6148	0.019*	0.183 (5)
H2'B	0.1360	0.3232	0.7667	0.019*	0.183 (5)
C3	0.18508 (7)	0.32823 (10)	0.5435 (2)	0.0179 (3)
H3A	0.2062	0.2962	0.6639	0.021*	0.817 (5)
H3B	0.2030	0.2947	0.4433	0.021*	0.817 (5)
H3C	0.2240	0.2887	0.6118	0.021*	0.183 (5)
H3D	0.1748	0.3051	0.4119	0.021*	0.183 (5)
C4	0.16459 (7)	0.51691 (10)	0.57248 (19)	0.0142 (2)
C5	0.26416 (7)	0.47390 (10)	0.52582 (19)	0.0140 (2)
C6	0.25763 (7)	0.57918 (10)	0.53377 (19)	0.0143 (2)
C7	0.31223 (7)	0.63821 (10)	0.5118 (2)	0.0166 (2)
H7	0.3111	0.7097	0.5143	0.020*
C8	0.36844 (7)	0.58455 (10)	0.4857 (2)	0.0158 (2)
C9	0.37001 (7)	0.47932 (11)	0.4812 (2)	0.0175 (3)
H9	0.4101	0.4471	0.4641	0.021*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.01399 (7)	0.02031 (8)	0.03740 (10)	−0.00406 (5)	0.00897 (6)	0.00137 (6)
S1	0.01303 (14)	0.01364 (14)	0.02374 (16)	0.00071 (11)	0.00854 (12)	−0.00036 (12)
N1	0.0120 (5)	0.0103 (4)	0.0206 (5)	−0.0002 (4)	0.0058 (4)	−0.0006 (4)
N2	0.0136 (5)	0.0117 (5)	0.0246 (6)	0.0011 (4)	0.0068 (4)	0.0003 (4)
N3	0.0131 (5)	0.0136 (5)	0.0244 (6)	0.0008 (4)	0.0065 (4)	−0.0004 (4)
C1	0.0156 (8)	0.0145 (7)	0.0240 (11)	−0.0020 (6)	0.0079 (7)	0.0010 (7)
C2	0.0155 (7)	0.0133 (7)	0.0255 (11)	−0.0024 (6)	0.0066 (7)	−0.0022 (6)
C1'	0.020 (4)	0.015 (3)	0.023 (5)	−0.005 (3)	0.009 (3)	−0.001 (3)
C2'	0.016 (3)	0.013 (3)	0.020 (4)	−0.001 (2)	0.005 (3)	0.002 (3)
C3	0.0153 (6)	0.0099 (5)	0.0301 (7)	−0.0009 (4)	0.0088 (5)	−0.0011 (5)
C4	0.0128 (5)	0.0125 (5)	0.0183 (6)	0.0014 (4)	0.0054 (4)	−0.0002 (5)
C5	0.0123 (5)	0.0122 (5)	0.0179 (6)	−0.0001 (4)	0.0043 (4)	−0.0003 (4)
C6	0.0132 (5)	0.0114 (5)	0.0187 (6)	0.0005 (4)	0.0041 (5)	0.0006 (4)
C7	0.0144 (6)	0.0128 (5)	0.0230 (6)	−0.0008 (4)	0.0047 (5)	0.0008 (5)
C8	0.0119 (5)	0.0153 (6)	0.0208 (6)	−0.0022 (4)	0.0046 (5)	0.0011 (5)
C9	0.0128 (6)	0.0160 (6)	0.0250 (7)	0.0010 (5)	0.0067 (5)	0.0002 (5)

Geometric parameters (Å, °)

Br1—C8	1.8986 (13)	C1'—C2'	1.521 (13)
S1—C4	1.7367 (14)	C1'—H1'A	0.9900
S1—C1	1.8211 (18)	C1'—H1'B	0.9900
S1—C1'	1.851 (6)	C2'—C3	1.536 (6)
N1—C4	1.3689 (17)	C2'—H2'A	0.9900
N1—C5	1.3836 (17)	C2'—H2'B	0.9900
N1—C3	1.4647 (17)	C3—H3A	0.9900
N2—C4	1.3243 (17)	C3—H3B	0.9900
N2—C6	1.3844 (17)	C3—H3C	0.9900
N3—C5	1.3286 (17)	C3—H3D	0.9900
N3—C9	1.3445 (18)	C5—C6	1.4067 (18)
C1—C2	1.521 (3)	C6—C7	1.3931 (19)
C1—H1A	0.9900	C7—C8	1.391 (2)
C1—H1B	0.9900	C7—H7	0.9500
C2—C3	1.522 (2)	C8—C9	1.3982 (19)
C2—H2A	0.9900	C9—H9	0.9500
C2—H2B	0.9900
C4—S1—C1	100.42 (7)	N1—C3—C2	111.68 (12)
C4—S1—C1'	100.1 (3)	N1—C3—C2'	111.7 (3)
C4—N1—C5	105.63 (11)	N1—C3—H3A	109.3
C4—N1—C3	128.79 (12)	C2—C3—H3A	109.3
C5—N1—C3	125.55 (11)	N1—C3—H3B	109.3
C4—N2—C6	103.85 (11)	C2—C3—H3B	109.3
C5—N3—C9	113.77 (12)	H3A—C3—H3B	107.9
C2—C1—S1	111.42 (14)	N1—C3—H3C	109.3
C2—C1—H1A	109.3	C2'—C3—H3C	109.3
S1—C1—H1A	109.3	N1—C3—H3D	109.3
C2—C1—H1B	109.3	C2'—C3—H3D	109.3
S1—C1—H1B	109.3	H3C—C3—H3D	107.9
H1A—C1—H1B	108.0	N2—C4—N1	114.41 (12)
C1—C2—C3	112.43 (15)	N2—C4—S1	121.96 (10)
C1—C2—H2A	109.1	N1—C4—S1	123.61 (10)
C3—C2—H2A	109.1	N3—C5—N1	126.67 (12)
C1—C2—H2B	109.1	N3—C5—C6	127.66 (13)
C3—C2—H2B	109.1	N1—C5—C6	105.67 (11)
H2A—C2—H2B	107.8	N2—C6—C7	131.50 (12)
C2'—C1'—S1	110.1 (6)	N2—C6—C5	110.44 (12)
C2'—C1'—H1'A	109.6	C7—C6—C5	118.06 (12)
S1—C1'—H1'A	109.6	C8—C7—C6	114.94 (12)
C2'—C1'—H1'B	109.6	C8—C7—H7	122.5
S1—C1'—H1'B	109.6	C6—C7—H7	122.5
H1'A—C1'—H1'B	108.2	C7—C8—C9	122.59 (13)
C1'—C2'—C3	111.2 (6)	C7—C8—Br1	119.37 (10)
C1'—C2'—H2'A	109.4	C9—C8—Br1	118.04 (10)
C3—C2'—H2'A	109.4	N3—C9—C8	122.97 (13)
C1'—C2'—H2'B	109.4	N3—C9—H9	118.5
C3—C2'—H2'B	109.4	C8—C9—H9	118.5
H2'A—C2'—H2'B	108.0
C4—S1—C1—C2	−42.19 (16)	C1—S1—C4—N1	10.57 (15)
C1'—S1—C1—C2	49.0 (7)	C1'—S1—C4—N1	−12.8 (4)
S1—C1—C2—C3	67.0 (2)	C9—N3—C5—N1	−179.92 (13)
C4—S1—C1'—C2'	44.5 (7)	C9—N3—C5—C6	0.4 (2)
C1—S1—C1'—C2'	−48.5 (7)	C4—N1—C5—N3	179.51 (14)
S1—C1'—C2'—C3	−69.0 (8)	C3—N1—C5—N3	−2.5 (2)
C4—N1—C3—C2	17.2 (2)	C4—N1—C5—C6	−0.78 (15)
C5—N1—C3—C2	−160.32 (14)	C3—N1—C5—C6	177.23 (13)
C4—N1—C3—C2'	−19.3 (4)	C4—N2—C6—C7	179.69 (15)
C5—N1—C3—C2'	163.2 (3)	C4—N2—C6—C5	−0.67 (16)
C1—C2—C3—N1	−52.1 (2)	N3—C5—C6—N2	−179.37 (14)
C1—C2—C3—C2'	44.8 (5)	N1—C5—C6—N2	0.92 (16)
C1'—C2'—C3—N1	54.3 (7)	N3—C5—C6—C7	0.3 (2)
C1'—C2'—C3—C2	−42.7 (5)	N1—C5—C6—C7	−179.37 (12)
C6—N2—C4—N1	0.15 (16)	N2—C6—C7—C8	178.98 (14)
C6—N2—C4—S1	−178.61 (10)	C5—C6—C7—C8	−0.6 (2)
C5—N1—C4—N2	0.41 (16)	C6—C7—C8—C9	0.3 (2)
C3—N1—C4—N2	−177.51 (14)	C6—C7—C8—Br1	179.90 (10)
C5—N1—C4—S1	179.16 (10)	C5—N3—C9—C8	−0.9 (2)
C3—N1—C4—S1	1.2 (2)	C7—C8—C9—N3	0.6 (2)
C1—S1—C4—N2	−170.77 (14)	Br1—C8—C9—N3	−179.09 (11)
C1'—S1—C4—N2	165.9 (4)