Studies in antiparastic agents: Part 11 - Synthesis of 5-substituted 2-alkyl/aryl-carbonylaminobenzimidazoles as orally effective anthelmintics

A series of 2-acetylamino-5(6)-substituted benzimidazoles (10-16), N,N'-di(5-benzoylbenzimidazol-2-yl)urea (17) and methyl 5(6)-substituted-benzimidazole-2-carbamates (18-25) has been synthesized. All the benzimidazoles (10-25) have been evaluated for their anthelmintic activity against a number of intestinal and tissue dwelling helminths. Compound 18 shows 100% elimination of Ancylostoma ceylanicum, Nippostrongylus brasiliensis, Syphacia obvelata, Hymenolepis nana and Cysticerus fasciolaris from rodents at a dose of 12.5-250 mg/kg by oral and parenteral routes of administrations. Compound 16 and 17 exhibit 74-100% reduction of microfilariae and adult worms of Litomosoides carinii and Acanthocheilonema viteae at a dose of 30-200 mg/kg x 5. When tested against Brugia malayi, 16 and 17 exhibit sterilization effect on adult female worms.