Synthesis and Analgesic, Anthelmintic, and Insecticidal Activity of 3,3-Dialkyl-1-(2-Phenylamino-2-Thioxoethyl)-3,4-Dihydroisoquinolinium Chlorides

Abstract

A series of 1,2,3,4-tetrahydroisoquinoline enaminothioamides were synthesized by reacting 1-methyl-3,3-dialkyl-3,4-dihydroisoquinolines with phenylisothiocyanate. Treatment of the obtained enamines with HCl gave 3,3-dialkyl-1-(2-phenylamino-2-thioxoethyl)-3,4-dihydroisoquinolinium chlorides. Benzo[f]isoquinoline derivatives were synthesized analogously. All hydrochlorides showed analgesic effects in the hot-plate test at the level of metamizole sodium. Isoquinolines with 6- and 7-alkoxy groups were most active. The hydrochloride of the thioamide containing benzo[f]isoquinoline and spirocyclopentane motifs had the greatest anthelmintic and insecticidal activities, which were similar to those of levamisole and diazinon.