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

The title compound, C(21)H(23)NO(4)S, 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%).