[5,6-bis-(3-alkoxy-carbonyl thio-ureido) benzimidazoles with anthelmintic activity]

The reaction of potassium thiocyanate with the methyl- and ethyl esters of chloroformic acid (V-VI) in acetone resulted in methoxy- and ethoxycarbonylisothiocyanates which were converted without isolation by means of an addition reaction with 2-alkyl-5,6-diaminobenzimidazoles (I-IV) into the pertinent 2-alkyl-5,6-bis (3-alkoxycarbonyl-2-thioureido) benzimidazoles (VII-XV). The substances obtained were tested for anthelmintic and anticoccidial effectiveness. In anthelmintic screening, substances VIII, IX, XI, XII, XIV and XV were significantly effective against the taenia Hymenolepis nana.