Novel Meta-Diamide Compounds Containing Sulfide Derivatives Were Designed and Synthesized as Potential Pesticides.

The meta-diamide ( m -diamide) insecticide, Broflanilide, was characterized by its high efficiency, low toxicity and lack of cross-resistance with traditional GABA receptors. In accordance with the principles of drug molecular design, easily derivable sulfur with diverse bioactivities was introduced while leading with the parent Broflanilide. Twelve novel m -diamide target compounds containing sulfide derivatives were synthesized through exploration guided by the literature. Their structures were confirmed by melting points, 1 H NMR, 13 C NMR and HRMS. Insecticidal activity assessments revealed that most target compounds A - D exhibited 100% lethality against Plutella xylostella ( P. xylostella ) and Aphis craccivora Koch ( A. craccivora ) at 500 mg·L-1 . Notably, for P. xylostella , compounds C-2 , C-3 , C-4 and D-2 demonstrated 60.00-100.00% insecticidal activity even at a concentration as low as 0.625 mg·L-1 . As determined by structure-activity relationship (SAR) analysis, compounds with R1 = CH3 and R2 = Br ( B-1 , C-2 and D-2 ) and sulfoxide compound C-3 contained 100.00% lethality against A. craccivora at 500 mg·L-1 , surpassing the lethality when leading with the parent Broflanilide in terms of efficacy. Consequently, it can be inferred that the sulfoxide compound ( C-3 ) requires further investigation as a potential active molecule for new insecticides. These explorations provide valuable references for future research on the synthesis and insecticidal activities of sulfide-containing m -diamide compounds.