Design, synthesis and insecticidal activity of novel semicarbazones and thiosemicarbazones derived from chalcone

Thirty semicarbazone and thiosemicarbazone derivatives (2a–w and 4a–g) from chalcones containing furan and thiophene ring were designed and synthesized. They were characterized by IR, 1H NMR, 13C NMR and HRMS. The crystal structure of compound 2r was characterized by single crystal X-ray diffraction. It crystallizes in the monoclinic system with space group P21/c. The insecticidal activity of the synthesized compounds was screened against Leucania separata and Pieris rapae using beta-cypermethrin as the comparative standard. The results displayed that most of them had remarkable insecticidal activity. Among them, compounds 2e–g showed better activity than beta-cypermethrin against L. separata and P. rapae. Compound 2p also possessed a better activity than beta-cypermethrin against P. rapae. The insecticidal activities of these compounds have been reported for the first time.