Due to serious side effects of benzimidazoles such as apoptosis and mitotic arrest, development of alternative anthelmintic drugs with comparable efficacy to target the acetylcholine receptors of parasites is considered very important to control this parasitic disease. Here we have developed an excellent method for synthesis of biscoumarins by employing a mild and efficient proline derived bifunctional thiourea catalyst bearing pyrrolidine and thiourea catalytic sites and tested their anthelmintic activity against helminth parasites Raillietina echinobothrida and Syphacia obvelata. The compounds 2a, 2j, 2k and 2o demonstrated much stronger anthelmintic activity against Raillietina echinobothrida in comparison to the standard drug, Praziquantel. Molecular docking simulations of the optimized compounds with b-tubulin showed excellent binding interactions with several amino acid residues of the active site and the docking scores with b-tubulin were found to be comparable to the in vitro anthelmintic activity.

A series of biscoumarins were synthesized and they showed excellent anthelmintic properties in comparison to conventional benzimidazoles.