Synthesis and biological evaluation of some novel 2-phenyl benzimidazole-1-acetamide derivatives as potential anthelmintic agents

Synthesis and biological evaluation of some novel 2-phenyl benzimidazole-1-acetamide derivatives as potential anthelmintic agents The present study describes synthesis of a series of 2-phenyl benzimidazole-1-acetamide derivatives and their evaluation for anthelmintic activity using Indian adult earthworms, Pheretima posthuma. The structure of the title compounds was elucidated by elemental analysis and spectral data. The compounds 4-({[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl]acetyl}amino) benzoic acid ( 3a ), N -ethyl-2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl] acetamide ( 3c ), N -benzyl-2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl] acetamide ( 3d ), N -(4-hydroxyphenyl)-2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl] acetamide ( 3f ), 2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl]- N -phenyl acetamide ( 3h ), 2-[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl]- N' -phenylacetohydrazide ( 3k ), 2-[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl]- N -(4-nitrophenyl) acetamide ( 3n ) and 2-[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl]- N -phenyl acetamide ( 3q ) were found better to paralyze worms whereas N -ethyl-2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl] acetamide ( 3c ), N-(4-nitrophenyl)-2-[2-(4-nitrophenyl)-1 H -benzimidazol-1-yl] acetamide ( 3e ), 4-({[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl] acetyl}amino) benzoic acid ( 3j ), 2-[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl]- N -ethyl acetamide ( 31 ) and 2-[2-(4-chlorophenyl)-1 H -benzimidazol-1-yl]- N -phenyl acetamide ( 3q ) were better to cause death of worms compared to the anthelmintic drug albendazole.