Synthesis,insecticidal activities,and SAR studies of novel piperazine-containing heterocyclic mono-/di-/tri-amide derivatives

Diamide compounds such as chlorantraniliprole, a famous anthranilic diamide insecticide targeting the insect ryanodine receptor (RyR), have received continuous attention in pesticide research during the past 15 years owing to their excellent insecticidal potentials. With the aim of discovering new heterocyclic pesticides used for crop protection, based on the structural information of compound M from the reported pharmacophore-based virtual screening for RyR insecticides and diamide compound, a series of new heterocyclic mono-, di-, and tri-amide derivatives containing piperazine moiety have been synthesized in this paper. The new compounds were identified and confirmed by melting point, ¹H NMR, ¹³C NMR and HRMS. Compound M was firstly validated for insecticidal activities, and the new synthesized compounds were all made comprehensive insecticidal evaluations against diamondback moth and oriental armyworm. The bioassay results showed that some of the compounds exhibit favorable insecticidal potentials, particularly some novel piperazine-containing heterocyclic mono-/di-/tri-amide derivatives such as 8g, 14a, 15a, 15g, 15i, 15j, 15k, 15l, and 15m could be used as new insecticidal leading structures for further study (e.g., towards diamondback moth, 15i-15m LC₅₀: 0.0022−0.0081 mg/L). The structure-activity relationships of the compounds discussed in detail provide useful guidance for further design and development of new insecticides.