The filaricidal activity of some derivatives of N-[2-(4-thiazolyl)benzimidazol-5-yl]benzamide against Brugia pahangi adults.

A series of analogues of N-[2-(4-thiazolyl)benzamidazol-5-yl]benzamide with halogen substituents on the benzamide ring was tested for activity against adult Brugia pahangi in the peritoneal cavities of jirds. None of the chloro, bromo or iodo analogues was active at 5 x 100 mg/kg by subcutaneous injection. The 2-fluoro, 3-fluoro and 4-fluoro analogues showed greater activity than the parent compound and the 2,5-difluoro analogue had the same activity as the parent. The 3-fluoro, 4-fluoro and 2,5-difluoro analogues were not active in cats treated per os with 5 x 50 mg/kg.