Synthesis, insecticidal activity and structure-activity relationship of 2-(3,3-Dichloro-2-propenyloxy)phenyl-containing phthalic acid diamide derivatives

A series of novel 2-(3,3-dichloro-2-propenyloxy)phenyl-containing phthalic acid diamide derivatives (3I-3IV) were designed and synthesized. Their chemical structures were characterized by ¹H NMR, mass spectrometry and elemental analyses. The insecticidal activities of these compounds against Plutella xylostella were evaluated at the concentration of 100 mg/L. Their insecticidal activity is effected by the substituent on the aliphatic amide moiety, which follows the trend of H (3I) >-SCH₃ (3II) and-S(O)₂CH₃ (3IV) >-OCH₃ (3III). Meanwhile, when the substituent (-CH₃,-CF₃,-Cl) on the aniline ring was introduced to the 3,3-dichloro-2-propenyloxy group in different positons, the meta-derivatives exhibit better insecticidal activity than the para-derivatives. Compared with the compounds bearing 3,3-dichloro-2-propenyloxy group on the 2-positon of the aniline ring, the compounds with that substituent on the 4-positon exhibit almost the same insecticidal activity trend but much better bioactivity.