Microwave assisted synthesis of novel benzimidazole derivatives as potent antileishmanial and antimalarial agents

Novel series of novel benzimidazole derivatives were synthesized by microwave assisted synthesis as green chemistry. Six novel benzimidazole derivatives were synthesized successfully in appreciable yields and characterized physicochemically. Furthermore, the synthesized compounds were screened for antileishmanial and antimalarial activity. Some of the synthesized compounds showed significant activity.Benzimidazole derivatives were synthesised and tested in vitro for activity against promastigotes of Leishmaniatropica and L. infantum. Most of the tested compounds resulted active against both Leishmania species, with IC50 values in the low micromolar/sub-micromolar range. 3-benzoylbenzimidazole derivative was 12-/7-fold more potent than miltefosine, but exhibited a further improved SI. Therefore, compounds 2c and 2e represent interesting hit compounds, susceptible of structural modification to improve their safety profiles. All the synthesized compound were evaluated for their antimalarial activity against a chloroquine and quinine sensitive strain of P. falciparum. All experiments were performed in duplicate and mean values of IC50. 2d and 2f compounds displayed excellent activity against the P. falciparum strain compared to quinine compared tochloroquine.All the remaining compounds were found to be less active against chloroquine sensitive strains of P. falciparum.