Synthesis and Mosquiticidal Activity of Novel Hydrazone Containing Pyrimidine Derivatives against Aedes aegypti

Background: Aedes aegypti is the main mosquito vector for the transmission of several serious diseases, including Japanese encephalitis, yellow fever, Zika, and dengue virus. Increasing resistance to the limited number of public health chemicals requires the evaluation of new chemicals as potential control products. Methods: Pyrimidine-based compounds have shown some efficacy for agricultural uses and as mosquitocidal products. In this paper, a series of novel pyrimidine acyl-hydrazone derivatives were synthesized. Their structures were elucidated by H-1 NMR and HRMS. Results: Mosquitocidal activity was assessed against immature and adult Ae. aegypti to determine efficacy and to guide further synthetic efforts. Bioassay using 1st instar Ae. aegypti produced about 33% mortality for compounds 4b and 4l but determined that most of the compounds exhibited minimal larvicidal activity at 1ug/ul after 24 hours of exposure. Conclusion: Compound 4m (N'-(4-bromobenzylidene)-2-((2-(diethylamino)-6-methylpyrimidin-4-yl) oxy)acetohydrazide) was the most effective adulticide in this synthetic group and exhibited 40% mortality at a concentration of 3.125 mu g/mosq.