Synthesis and Crystal Structures of 5-Acetyl-4-(4-methoxyphenyl)-6-methyl-2-(methylsulfanyl)pyridine-3-carbonitrile and 5-Acetyl-2-[(cyanomethyl)sulfanyl]-4-(4-methoxyphenyl)-6-methylpyridine-3-carbonitrile

The first one (I) of the two related compounds, C17H16N2O2S, crystallizes in the monoclinic space group P21/c with Z = 4, while the second one (II), C18H15N3O2S, crystallizes in the monoclinic space group P-1 with Z = 4. There are two independent molecules in the asymmetric unit of compound (II). As expected, the pyridine rings are almost planar (r.m.s. deviation = 0.002 Å). In the molecules A and B of the compound II, the substituents (except methyl and cyano groups) attached to the pyridine ring, are inclined to the different directions. In the crystal of compound I, molecules are arranged into the parallel layers to the (001) plane which there exist weak π-π interactions in the c-direction. In the crystal of compound II, molecules are linked by C—H···O hydrogen bonds, forming infinite C(9) chains along the b-axis. Furthermore, C—H···π interactions contribute to the stabilization of molecular packing. Elham A. Al-Taifi et al. 43