Nowadays heterocyclic compounds become unavoidable structural motifs and building blocks in
organic and medicinal chemistry. Since benzimidazoles and benzothiazoles as one of the most
important nitrogen heterocycles have great and versatile biological activities, these benzazoles
become important structural scaffolds in the rational design of novel drugs in medicinal and
pharmaceutical chemistry. These nitrogen scaffolds could be found in a variety of bioactive natural
and synthetic medical and biochemical agents, which possess different chemical and pharmacological
features. Within this work we present the synthesis, structural characterization and biological
evaluation of methoxy and hydroxy substituted 2-benzimidazole and 2-benzothiazole derivatives
bearing either nitro or protonated amino group at the benzazole scaffold (Figure 1). The targeted
compounds were prepared by using conventional and well-optimized reactions of organic chemistry
for the synthesis and cyclocondensation of benzimidazole and benzothiazole nuclei. All synthesized
compounds were structurally characterized by means of 1H and 13C NMR spectroscopy. The
antiproliferative activity was evaluated on the panel of human cancer cells in vitro. Some of tested
compounds showed prominent antiproliferative activity. Obtained results revealed the strong
influence of the substituents placed at the phenyl as well as on the benzazole nuclei on biological
activity.
