Antiparasitic agents. 3. Synthesis and anthelmintic activities of novel 2-pyridinyl-5-isothiocyanatobenzimidazoles.

The preparation and anthelmintic activities of a series of 2-pyridinyl-5-isothiocyanatobenzimidazoles are described. In the primary oral mouse screen, six derivatives showed 100% taeniacidal activity at 0.2% in diet. The most active member in this series, 1c, is potentially an effective gastrointestinal nematocide in sheep at 50 mg/kg po.