Synthesis, crystal structure and larvicidal activity of novel diamide derivatives against Culex pipiens

Background: Culex is an important mosquito as vectors for the transmission of serious diseases, such as filariasis, West Nile virus, dengue, yellow fever, chikungunya and other encephalitides. Nearly one billion people in the developing countries are at risk. In order to discover new bioactive molecules and pesticides acting on mosquito, we designed active amide structure and synthesized a series of novel diamide derivatives. Results: A series of novel diamide derivatives were designed and synthesized. Their structures were characterized by H-1 NMR, FTIR and HRMS. The single crystal structure of compound 6n was determined to further elucidate the structure. Biological activities of these compounds were tested. Most of them exhibited higher mosquito larvicidal activity. Especially compound 6r displayed relatively good activity to reach 70% at 2 mu g/mL. Conclusion: A practical synthetic route to amide derivatives by the reaction of amide with another acid is presented. This study suggests that the diamide derivatives exhibited good effective against mosquito.