In search of novel neonicotinoid insecticides with potent bioactivities, a series of 1,2-dithiocyclopentenone derivatives were designed and synthesized by introducing dithiocyclopentenone into neonicotinoids skeleton. The structures of all compounds were confirmed by nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS). Biological activities of all the title compounds were evaluated systematically. Preliminary bioassays indicated that all synthesized compounds exhibited moderate insecticidal activities. 4-Chloro-5-(((6-chloropyridin-3-yl)methyl)(methyl)amino)-3H-1,2-di-thiol-3-one (3a), 4-chloro-5-(((6-chloropyridin-3-yl)methyl)(ethyl)amino)-3H-1,2-dithiol-3-one (3b), 4-chloro-5-(((6-chloro-pyridin-3-yl)methyl)(propyl)amino)-3H-1,2-dithiol-3-one (3c) and 4-chloro-5-(((6-chloropyridin-3-yl)methyl)(2,2-difluoro-ethyl)amino)-3H-1,2-dithiol-3-one (3g) exhibited >90% mortality rate against Aphis craccivora at 100 μg/mL. Compound 3g exhibited 40% insecticidal activity to aphids at 4 μg/mL and >70% mortality rate against Nilaparvata Lugens at 100 μg/mL, and could be utilized in insecticide research with further optimization.

Key words: neonicotinoid insecticide, dithiocyclopentenone, synthesis, insecticidal activity