Synthesis and potential anthelmintic activity of methyl-5-(4-salicyloyl-piperazin-1-yl)-benzimidazole-2-carbamates.

A series of methyl-5-(4-salicyloyl-piperazin-1-yl)-benzimidazole-2-carba mates (IX) has been prepared. 5-(4-Salicyloyl-piperazin-1-yl)-2-nitro anilines (VII) have been synthesized starting from 5-piperazino-2-nitro anilines and salicyloyl chlorides. Catalytic reduction of VII with Pd/C, followed by treatment with 1,3-dicarbomethoxy-S-methyl isothiourea, yielded the corresponding carbamates (IX), the anthelmintic activity of which was studied. Compound IXa significantly reduced the numbers of preadults, adults and encysted T. spiralis larvae in experimental mice.