Synthesis and Antinociceptive, Anthelmintic, and Larvicidal Activities of 4-(3,3-Dimethyl-3,4-Dihydroisoquinolin-1-Ylthio)Aniline Hydrochlorides

Ritter cyclocondensation of 3,4-(R)2-dimethylbenzylcarbinols with thiocyanatoanilines was used to obtain 4-[6,7-(R)2-3,3-dimethyl-3,4-dihydroisoquinolin-1-ylthio]anilines (R = H, MeO). A benzo[f]isoquinoline derivative was obtained similarly. 4-Thiocyanatoaniline, 2-methyl-4-thiocyanatoaniline, 2-thiocyanato-4-aminoethylbenzene, and 4,4′-dithiocyanatodiphenylamine were used as the thiocyanatoanilines. The hydrochlorides of the obtained compounds were used for biological tests. All compounds exhibited an analgesic effect in the hot-plate test that exceeded that of metamizole sodium. Five of the seven compounds exhibited anthelmintic activity. The most active compound caused the death of worms 14.3 times faster than pyrantel. The larvicidal activity of the same compound was 1.63 times greater than that of diazinon for reducing the time of death of larvae.