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].

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 C 9 H 10 N 2 S ( 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 ππ interactions are observed in the crystal structure.
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.

Figure 1
A molecule of C 9 H 10 N 2 S with atom labels and 50% probability displacement ellipsoids for non-hydrogen atoms.

Figure 2
Crystal structure packing viewed down the c axis with C-H···N interactions shown as dotted lines.