N-(4-Chloropyridin-2-yl)-N-(4-methylphenylsulfonyl)acetamide

The crystal structure of the title compound, C14H13ClN2O3S, features a three-dimensional network stabilized by intermolecular C—H⋯O hydrogen bonds between the molecules. The 4-methylphenylsulfonyl ring forms a dihedral angle of 30.6 (1)° with the 4-chloropyridine ring.

The crystal structure of the title compound, C 14 H 13 ClN 2 O 3 S, features a three-dimensional network stabilized by intermolecular C-HÁ Á ÁO hydrogen bonds between the molecules. The 4-methylphenylsulfonyl ring forms a dihedral angle of 30.6 (1) with the 4-chloropyridine ring.

Comment
In recent years, compounds with the 2-aminopyridine moiety exhibited interesting biological activities like the 2-alkylaminopyridinyl or 2-acylaminopyridinyl imidazole derivatives as p38α mitogen-activated protein kinase (p38α MAPK) inhibitors. The N-protected 4-chloropyridine is an important precursor to block the nucleophilic and basic properties of the amino-group in the C2 position of the pyridine ring. The analysis of the crystal structure shows that the aromatic C18-Hgroup of the 4-chloropyridine ring of one molecule interacts with the oxygen-atom O9 of the sulfonyl group of another molecule related to the first by centre of symmetry with a distance of H18···O9 2.47 Å. Furthermore, the aromatic C3-H group of the 4-methylphenylsulfonyl ring forms an intermolecular C3-H3···O13_a hydrogen bond (2.46 Å) to the oxygen atom O13 of the acetamide moiety of a third molecule. An additional hydrogen bond was observed between the methylgroup C14-H 3 of the acetamide moiety and the oxygen-atom O10 of the sulfonyl group of a further molecule, whereas the O10···H14B distance is 2.50 Å. The dihedral angle between the 4-methylphenylsulfonyl ring and the 4-chloropyridine ring is 30.6 (1)°.

Experimental
Synthesis of chloromethyl methyl ether as a solution of toluene: To a solution of dimethoxymethane (44.3 ml, 0.50 mol, 1 equiv) and Zn(OAc) 2 (9.2 mg, 0.01%) in toluene (133 ml) was added acetyl chloride (35.5 ml, 0.50 mol, 1 equiv). During the next 15 min, the reaction mixture warmed slowly at T = 318 K, and then cooled to ambient temperature over 3 h.
The progress was again monitored until NMR analysis indicated complete conversion. The solution of MOMCl in toluene prepared using this stoichiometry is approximately 2.1 M.
supplementary materials sup-2 Suitable crystals of the byproduct N-(4-chloropyridin-2-yl)-N-tosylacetamide for X-ray were obtained by slow evaporation at T = 298 K of a solution mixture of EtOAc/hexane.

Refinement
Hydrogen atoms were placed at calculated positions with C-H = 0.95 Å (aromatic) or 0.98-0.99 Å (sp 3 C-atom) and refined in the riding-model approximation with isotropic displacement parameters (set at 1.2-1.5 times of the U eq of the parent atom). Fig. 1. View of compound I. Displacement ellipsoids are drawn at the 50% probability level. 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 Rfactors(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.