An efficient synthesis of rearranged new biologically active benzimidazoles derived from 2-formyl carvacrol

A new series of benzimidazole derivatives was synthesized by one-pot two-step reaction as a result of unexpected rearrangement during reaction of 2-formyl carvacrol and corresponding 2-phenylenediamines in DMF, by using Na 2 S 2 O 5 as an oxidizing reagent. The newly synthesized compounds were characterized by 1 H NMR, 13 C NMR, FT-IR, mass spectroscopy techniques, and single-crystal X-ray crystallography. The docking studies of all nine compounds were carried out against the active site of the Plasmodium falciparum dihydroorotate dehydrogenase enzyme. To inspect their antimalarial, antimicrobial, and antioxidant activity, all the synthesized compounds were screened in vitro for their antimalarial activity against the malaria parasite Plasmodium falciparum strain and four bacterial as well as three fungal strains. The biological screening revealed that some synthesized compounds have very good antimalarial activity. The physicochemical properties were calculated for all the synthesized benzimidazoles and were found to be good oral bioavailability drugs as resolute by Lipinski's rule. Graphic abstract