(2 E ,2′ E )-2,2′-(1,2,4-Thiadiazole-3,5-diyl)bis[3-arylacrylonitriles]: Synthesis and Antidote Activity Towards 2,4-D Herbicide

Oxidation of ( Е )-3-aryl-2-cyanothioacrylamides under the action of the Et 2 S(O)–HCl system leads to the formation of (2 Е ,2′ E )-2,2′-(1,2,4-thiadiazole-3,5-diyl)bis[3-arylacrylonitriles] in 54–91% yields. Structure of the obtained compounds was confirmed by the two-dimensional NMR spectroscopy data. A plausible reaction mechanism was discussed. Two compounds showed a pronounced antidote effect against 2,4-D herbicide in a laboratory experiment on sunflower seedlings in the absence of growth-stimulating activity.