Crystal structure of 2-(1-methyl­eth­yl)-1,3-thia­zolo[4,5-b]pyridine

In the title mol­ecule, C₉H₁₀N₂S, one of the methyl groups is almost co-planar with the thia­zolo­pyridine rings with a deviation of 0.311 (3) Å from the least-squares plane of the thia­zolo­pyridine group. In the crystal, weak C-H...N hydrogen-bonding inter­actions lead to the formation of chains along [011].

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.021
• wR factor = 0.057
• Data-to-parameter ratio = 12.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT034_ALERT_1_C No Flack Parameter Given. Z > Si, NonCentro ....     Please Do !
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          4 Report
PLAT915_ALERT_3_C Low Friedel Pair Coverage ......................         53 %

Alert level G
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         15 Note
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......     Please Check

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

   1 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
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Chemical context

Thia­zolo­pyridines have been efficiently synthesized and in high yield using different synthetic procedures (Smith et al., 1994, 1995; El-Hiti, 2003; Johnson et al., 2006; Thomae et al., 2008; Rao et al., 2009; Lee et al., 2010; Luo et al., 2015). During our continuing research towards the development of novel synthetic routes for the production of heterocyclic compounds, we have synthesised the title compound 2-(methyl­ethyl)-1,3-thia­zolo[4,5-b]pyridine in high yield (Smith et al., 1995). The X-ray structures for related compounds have been reported (Yu et al., 2007; El-Hiti et al., 2014).

S2. Structural commentary

The asymmetric unit of the title compound consists of a single molecule of C₉H₁₀N₂S (Fig. 1). In the molecule, one of the methyl groups is almost co-planar with the thia­zolo­pyridine ring. The deviations from the least-squares plane of the thia­zolo­pyridine group are 0.311 (3)Å and 1.269 (3)Å for C8 and C9 respectively, corresponding to torsion angles N1—C1—C7—C8 and N1—C1—C7—C9 of 169.47 (19) and -65.9 (3)°, respectively.

Weak C—H···N hydrogen-bonding inter­actions occur in the structure to form chains along [011] (Fig. 2, Table 1). No π–π inter­actions are observed in the crystal structure.

S3. Synthesis and crystallization

2-(1-Methyl­ethyl)-1,3-thia­zolo[4,5-b]pyridine was obtained in 98% yield from acid hydrolysis (HCl, 5 M) of 3-(diiso­propyl­amino­thio­carbonyl­thio)-2-(1-methyl­ethyl­carbonyl­amino)­pyridine under reflux for 5 h (Smith et al., 1995). Crystallization of the crude product from di­ethyl ether gave colourless crystals of the title compound. The spectroscopic and analytical data for the title compound were consistent with those reported previously (Smith et al., 1995).

S4. Refinement details

H atoms were positioned geometrically and refined using a riding model with U_iso(H) constrained to be 1.2 times U_eq for the atom it is bonded to except for methyl groups where it was 1.5 times with free rotation about the C—C bond. Although not of relevance with this achiral compound, the absolute structure factor (Flack, 1983) was determined as 0.031 (11) for 434 Friedel pairs.

Related literature

For related compounds, see: Smith et al. (1994, 1995); El-Hiti (2003); Johnson et al. (2006); Thomae et al. (2008); Rao et al. (2009); Lee et al. (2010); Luo et al. (2015). For the X-ray crystal structures of related compounds, see: Yu et al. (2007); El-Hiti et al. (2014).

Structure description

Thia­zolo­pyridines have been efficiently synthesized and in high yield using different synthetic procedures (Smith et al., 1994, 1995; El-Hiti, 2003; Johnson et al., 2006; Thomae et al., 2008; Rao et al., 2009; Lee et al., 2010; Luo et al., 2015). During our continuing research towards the development of novel synthetic routes for the production of heterocyclic compounds, we have synthesised the title compound 2-(methyl­ethyl)-1,3-thia­zolo[4,5-b]pyridine in high yield (Smith et al., 1995). The X-ray structures for related compounds have been reported (Yu et al., 2007; El-Hiti et al., 2014).

The asymmetric unit of the title compound consists of a single molecule of C₉H₁₀N₂S (Fig. 1). In the molecule, one of the methyl groups is almost co-planar with the thia­zolo­pyridine ring. The deviations from the least-squares plane of the thia­zolo­pyridine group are 0.311 (3)Å and 1.269 (3)Å for C8 and C9 respectively, corresponding to torsion angles N1—C1—C7—C8 and N1—C1—C7—C9 of 169.47 (19) and -65.9 (3)°, respectively.

Weak C—H···N hydrogen-bonding inter­actions occur in the structure to form chains along [011] (Fig. 2, Table 1). No π–π inter­actions are observed in the crystal structure.

For related compounds, see: Smith et al. (1994, 1995); El-Hiti (2003); Johnson et al. (2006); Thomae et al. (2008); Rao et al. (2009); Lee et al. (2010); Luo et al. (2015). For the X-ray crystal structures of related compounds, see: Yu et al. (2007); El-Hiti et al. (2014).

Synthesis and crystallization

2-(1-Methyl­ethyl)-1,3-thia­zolo[4,5-b]pyridine was obtained in 98% yield from acid hydrolysis (HCl, 5 M) of 3-(diiso­propyl­amino­thio­carbonyl­thio)-2-(1-methyl­ethyl­carbonyl­amino)­pyridine under reflux for 5 h (Smith et al., 1995). Crystallization of the crude product from di­ethyl ether gave colourless crystals of the title compound. The spectroscopic and analytical data for the title compound were consistent with those reported previously (Smith et al., 1995).

Refinement details

H atoms were positioned geometrically and refined using a riding model with U_iso(H) constrained to be 1.2 times U_eq for the atom it is bonded to except for methyl groups where it was 1.5 times with free rotation about the C—C bond. Although not of relevance with this achiral compound, the absolute structure factor (Flack, 1983) was determined as 0.031 (11) for 434 Friedel pairs.

Computing details

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and CHEMDRAW Ultra (Cambridge Soft, 2001).

Figures

	Fig. 1. A molecule of C9H10N2S with atom labels and 50% probability displacement ellipsoids for non-hydrogen atoms.
	Fig. 2. Crystal structure packing viewed down the c axis with C—H···N interactions shown as dotted lines.

2-(1-Methylethyl)-1,3-thiazolo[4,5-b]pyridine

Crystal data

C9H10N2S	Dx = 1.355 Mg m^−3
Mr = 178.25	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, Pna21	Cell parameters from 2276 reflections
a = 9.6376 (2) Å	θ = 6.3–73.8°
b = 10.1602 (2) Å	µ = 2.81 mm^−1
c = 8.9254 (2) Å	T = 150 K
V = 873.98 (3) Å^3	Block, colourless
Z = 4	0.23 × 0.20 × 0.14 mm
F(000) = 376

Data collection

Agilent SuperNova, Dual, Cu at zero, Atlas diffractometer	1366 independent reflections
Radiation source: sealed X-ray tube, SuperNova (Cu) X-ray Source	1351 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.012
Detector resolution: 10.5082 pixels mm^-1	θmax = 74.0°, θmin = 6.3°
ω scans	h = −11→10
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014)	k = −12→8
Tmin = 0.897, Tmax = 0.940	l = −10→10
2848 measured reflections

Refinement

Refinement on F^2	1 restraint
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.021	H-atom parameters constrained
wR(F^2) = 0.057	w = 1/[σ^2(Fo^2) + (0.0375P)^2 + 0.1081P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
1366 reflections	Δρmax = 0.19 e Å^−3
111 parameters	Δρmin = −0.20 e Å^−3

Special details

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.

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

	x	y	z	Uiso*/Ueq
C1	0.13501 (18)	0.59856 (18)	0.8660 (2)	0.0227 (4)
C2	0.23657 (17)	0.67547 (17)	1.1015 (2)	0.0208 (3)
C3	0.29550 (18)	0.56187 (17)	1.0365 (2)	0.0203 (3)
C4	0.2865 (2)	0.72261 (17)	1.2365 (3)	0.0257 (4)
H4	0.2483	0.7985	1.2829	0.031*
C5	0.39534 (19)	0.6532 (2)	1.3007 (3)	0.0279 (4)
H5	0.4342	0.6813	1.3931	0.034*
C6	0.44760 (19)	0.54145 (19)	1.2283 (3)	0.0273 (4)
H6	0.5220	0.4959	1.2752	0.033*
C7	0.05003 (18)	0.57871 (19)	0.7259 (3)	0.0271 (4)
H7	0.0177	0.4852	0.7251	0.033*
C8	−0.0783 (2)	0.6663 (2)	0.7204 (3)	0.0365 (5)
H8A	−0.1375	0.6475	0.8070	0.055*
H8B	−0.1299	0.6488	0.6279	0.055*
H8C	−0.0499	0.7589	0.7227	0.055*
C9	0.1411 (2)	0.5992 (3)	0.5875 (3)	0.0421 (6)
H9A	0.1666	0.6923	0.5796	0.063*
H9B	0.0897	0.5727	0.4977	0.063*
H9C	0.2253	0.5457	0.5966	0.063*
N1	0.23563 (16)	0.52156 (16)	0.9037 (2)	0.0241 (3)
N2	0.40055 (14)	0.49434 (16)	1.0985 (2)	0.0254 (4)
S1	0.10273 (4)	0.73079 (4)	0.98822 (7)	0.02515 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0205 (8)	0.0253 (8)	0.0224 (10)	−0.0013 (7)	0.0032 (7)	−0.0026 (8)
C2	0.0212 (8)	0.0210 (7)	0.0203 (9)	−0.0011 (6)	0.0033 (6)	−0.0004 (7)
C3	0.0199 (7)	0.0206 (7)	0.0204 (9)	−0.0026 (6)	0.0032 (6)	−0.0024 (7)
C4	0.0292 (9)	0.0258 (9)	0.0221 (9)	−0.0028 (7)	0.0018 (8)	−0.0061 (8)
C5	0.0302 (9)	0.0353 (11)	0.0184 (9)	−0.0058 (7)	−0.0024 (7)	0.0002 (9)
C6	0.0258 (8)	0.0303 (9)	0.0259 (9)	0.0005 (7)	−0.0035 (8)	0.0042 (8)
C7	0.0266 (8)	0.0293 (9)	0.0254 (9)	−0.0036 (7)	−0.0032 (8)	−0.0030 (8)
C8	0.0293 (9)	0.0428 (12)	0.0374 (13)	0.0037 (9)	−0.0127 (9)	−0.0071 (11)
C9	0.0351 (11)	0.0705 (16)	0.0207 (11)	−0.0072 (11)	−0.0024 (8)	−0.0025 (11)
N1	0.0231 (7)	0.0264 (8)	0.0229 (8)	0.0012 (6)	0.0001 (6)	−0.0067 (7)
N2	0.0238 (8)	0.0239 (7)	0.0284 (9)	0.0024 (6)	−0.0016 (6)	−0.0002 (7)
S1	0.0242 (2)	0.0266 (2)	0.0246 (2)	0.00703 (13)	−0.0007 (2)	−0.0048 (2)

Geometric parameters (Å, º)

C1—N1	1.291 (2)	C6—N2	1.334 (3)
C1—C7	1.508 (3)	C6—H6	0.9500
C1—S1	1.7585 (19)	C7—C8	1.524 (3)
C2—C4	1.383 (3)	C7—C9	1.530 (3)
C2—C3	1.411 (2)	C7—H7	1.0000
C2—S1	1.7325 (19)	C8—H8A	0.9800
C3—N2	1.342 (2)	C8—H8B	0.9800
C3—N1	1.380 (2)	C8—H8C	0.9800
C4—C5	1.388 (3)	C9—H9A	0.9800
C4—H4	0.9500	C9—H9B	0.9800
C5—C6	1.400 (3)	C9—H9C	0.9800
C5—H5	0.9500
N1—C1—C7	122.91 (17)	C8—C7—C9	111.1 (2)
N1—C1—S1	115.73 (15)	C1—C7—H7	107.6
C7—C1—S1	121.36 (14)	C8—C7—H7	107.6
C4—C2—C3	120.08 (17)	C9—C7—H7	107.6
C4—C2—S1	130.92 (14)	C7—C8—H8A	109.5
C3—C2—S1	108.98 (14)	C7—C8—H8B	109.5
N2—C3—N1	121.16 (16)	H8A—C8—H8B	109.5
N2—C3—C2	123.53 (18)	C7—C8—H8C	109.5
N1—C3—C2	115.30 (16)	H8A—C8—H8C	109.5
C2—C4—C5	116.51 (17)	H8B—C8—H8C	109.5
C2—C4—H4	121.7	C7—C9—H9A	109.5
C5—C4—H4	121.7	C7—C9—H9B	109.5
C4—C5—C6	119.6 (2)	H9A—C9—H9B	109.5
C4—C5—H5	120.2	C7—C9—H9C	109.5
C6—C5—H5	120.2	H9A—C9—H9C	109.5
N2—C6—C5	124.73 (18)	H9B—C9—H9C	109.5
N2—C6—H6	117.6	C1—N1—C3	110.99 (16)
C5—C6—H6	117.6	C6—N2—C3	115.54 (16)
C1—C7—C8	112.90 (18)	C2—S1—C1	89.00 (9)
C1—C7—C9	109.85 (15)
C4—C2—C3—N2	−0.3 (3)	C7—C1—N1—C3	−179.88 (16)
S1—C2—C3—N2	−179.06 (14)	S1—C1—N1—C3	0.6 (2)
C4—C2—C3—N1	178.46 (16)	N2—C3—N1—C1	178.62 (17)
S1—C2—C3—N1	−0.3 (2)	C2—C3—N1—C1	−0.1 (2)
C3—C2—C4—C5	0.4 (3)	C5—C6—N2—C3	0.0 (3)
S1—C2—C4—C5	178.89 (15)	N1—C3—N2—C6	−178.61 (17)
C2—C4—C5—C6	−0.4 (3)	C2—C3—N2—C6	0.1 (3)
C4—C5—C6—N2	0.2 (3)	C4—C2—S1—C1	−178.11 (19)
N1—C1—C7—C8	169.47 (19)	C3—C2—S1—C1	0.50 (14)
S1—C1—C7—C8	−11.0 (2)	N1—C1—S1—C2	−0.64 (15)
N1—C1—C7—C9	−65.9 (3)	C7—C1—S1—C2	179.79 (16)
S1—C1—C7—C9	113.64 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···N1^i	0.95	2.51	3.391 (2)	153

Symmetry code: (i) −x+1/2, y+1/2, z+1/2.