Syntheses, crystal structures and Hirshfeld surface analysis of 2-(benzyl-sulfan-yl)-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole and 2-[(2-chloro-6-fluoro-benz-yl)sulfan-yl]-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole.

The title compounds were synthesized by alkyl-ation of 5-[(4-di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole-2-thiol with benzyl chloride or 2-chloro-6-fluoro-benzyl chloride in the presence of potassium carbonate. The yields of 2-(benzyl-sulfan-yl)-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole, C 17 H 17 N 3 OS (I), and 2-[(2-chloro-6-fluoro-benz-yl)sulfan-yl]-5-[4-(di-methyl-amino)-phen-yl]-1,3,4-oxa-diazole, C 17 H 15 ClFN 3 OS (II), were 96 and 92%, respectively. In the crystal structures of (I) and (II), C-H⋯π inter-actions are observed between neighboring mol-ecules. Hirshfeld surface analysis indicates that H⋯H and H⋯C/C⋯H inter-actions make the most important contributions to the crystal packing.