Multistep synthesis of 1-[{(5-alkenyl/hydroxyalkenylsubstituted)-1,3,4-oxadiazol-2-yl}-methyl]-2-methyl-1H-benzimidazole series and in vitro anticancer screening, SAR studies

A novel series of hydroxy and non-hydroxy long chain substituted 1,3,4-oxadiazole moiety bearing 2-methyl-1H-benzimidazoles 15(a-d) have been synthesized from cyclization reaction of 2-(2-methyl-1H-benzimidazol-1-yl) acetohydrazide (13) with different unsaturated hydroxy and non-hydroxy fatty esters in the presence of phosphorus oxychloride and product obtained in appreciable yield. Compound (13) was synthesized from the corresponding ethyl (2-methyl-1H-benzimidazol-1-yl) acetate (12) and 2-methyl-1H-benzimidazole (11). All the synthesized compounds were characterized with the help of IR, H-1 NMR, C-13 NMR, and mass spectral studies. These compounds were tested for cytotoxic (or antiproliferative) activity against normal human blood cells (PBMCs), Hep3B (human hepatocellular carcinoma), MCF 7 (human breast adenocarcinoma), and HeLa (human cervical carcinoma) cell lines.