Synthesis and anthelmintic properties of arylquinolines with activity against drug-resistant nematodes.

2,4-Disubstituted quinolines with additional substituents in positions 5-8 have been found to have anthelmintic properties. A number of 2,4-dimethoxy-6- or 8-arylquinolines have potent activity against the sheep nematode Haemonchus contortus, with LD99 values of the same order of magnitude as levamisole. These arylquinolines maintain their activity against levamisole-, ivermectin- and thiabendazole-resistant strains of H. contortus.