2-(Ethylsulfinyl)imidazo[1,2-a]pyridine-3-sulfonamide

The supramolecular structure of the title compound, C9H11N3O3S2, is defined by two intermolecular hydrogen bonds. Pairs of N—H⋯N hydrogen bonds link the molecules into centrosymmetric dimers and N—H⋯O hydrogen bonds link the dimers into a tubular chain structure running parallel to the a axis.

The supramolecular structure of the title compound, C 9 H 11 N 3 O 3 S 2 , is defined by two intermolecular hydrogen bonds. Pairs of N-HÁ Á ÁN hydrogen bonds link the molecules into centrosymmetric dimers and N-HÁ Á ÁO hydrogen bonds link the dimers into a tubular chain structure running parallel to the a axis.
The supramolecular structure is defined by the N3-H3B···N1 hydrogen bond which links the molecules into centrosymmetric dimers lying across the centre-of-symmetry at (0.5,0.5,0.5) and the N3-H3B···O1 hydrogen bond which links the dimers into tubular chains which run parallel to the a-axis, Table 1 and Figure 2.
Experimental m-chloroperoxybenzoic acid (1.88 g, 8.22 mmol) in 100 ml CH 2 Cl 2 was added dropwise to a solution of 2-ethylthioimidazo[1,2-a]pyridine-3-sulfonamide (2.2 g, 8.22 mmol) in 200 ml CH 2 Cl 2 in an ice water bath. The suspension was stirred at 0-5°C for more than 3 h, and filtered. After removing the solvent, and the crude product was recrystallized in MeOH to give white crystalline product (1.24 g, 55% yield)). The melting point of the product was 203-205°C.

Refinement
H atoms were treated as riding atoms with C-H(aromatic), 0.93 Å, and C-H(CH 2 ), 0.97\$A with U iso = 1.2Ueq(C) and The hydrogen atoms attached to N3 were located on a difference Fourier map and allowed to ride at these positions.
These positions were confirmed in a final difference Fourier map.

Figure 1
A view of (1) with our numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

2-(Ethylsulfinyl)imidazo[1,2-a]pyridine-3-sulfonamide
Crystal data C 9 H 11 N 3 O 3 S 2 M r = 273.33 Triclinic, P1 Hall symbol: -P 1 a = 8.3761 (9) Å b = 8.5438 (9) Å c = 9.1083 (10) Å α = 88.832 (2) where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.29 e Å −3 Δρ min = −0.30 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.