Design, synthesis, insecticidal activity and structure-activity relationship of 3,3-dichloro-2-propenyloxy-containing phthalic acid diamide structures.

BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3-dichloro-2-propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides.
RESULTS: Thirty-one new phthalic acid diamides were obtained, and these were characterised by (1) H and (13) C NMR. The structure of N(2) -[1,1-dimethyl-2-(methoxy)ethyl]-3-iodo-N(1) -[4-(3,3-dichloro-2-propenyloxy)-3-(trifluoromethyl)phenyl]-1,2-benzenedicarboxamide was determined by X-ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure-activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance.
CONCLUSION: A series of novel phthalic acid diamides containing a 3,3-dichloro-2-propenyloxy group at the 4-position of the aniline ring were designed and synthesised. Structure-activity relationships with the parent structure provided information that could direct further investigation on structure modification.