Unexpected synthesis and crystal structure of N-{2-[2-(2-acetylethenyl)phenoxy]ethyl}-N-ethenyl-4-methylbenzenesulfonamide

The title compound, C21H23NO4S, obtained by alkaline treatment of 1,5-bis(1-phenoxy)-3-azapentane at moderate heating, is a N-tosylated secondary vinylamine. An intramolecular S=O⋯H - C hydrogen bond generates a 13-membered ring. The benzalacetone moiety adopts a trans conformation with respect to the C=C double bond, which is slightly longer than usual due to the conjugation with a neighbouring acetyl group. Theoretical predictions of potential biological activities were performed, suggesting that the title compound can inhibit gluconate 2-dehydrogenase (85% probability), as well as to act as a mucomembranous protector (73%). © 2020.