Synthesis and Biological Activity of A Novel Acaricide, Pyflubumide

Pyflubumide is a novel acaricide with a unique chemical structure that contains a methoxy-substituted hexafluoroisopropyl group on the anilino moiety The compound has shown remarkable activity against spider mites including strains resistant to existing acaricides collected from the fields of Japan. Since carboxin was developed in 1966, various carboxamides with the same mode of action, i.e., succinate dehydrogenase inhibitors, have been created and developed. Although succinate dehydrogenase plays an important role in energy metabolism in aerobic organisms, the practical usage of the carboxamides has been primarily limited to disease control and an acaricidal activity has never been reported. The study to create a new carboxamide molecule revealed that introducing a fluoroalkyl group at the 4'-position of the aniline molecule remarkably enhanced the acaricidal activity. This finding prompted extensive research to ultimately identify pyflubumide. In this report, details of the structure-activity relationships from the lead compound to pyflubumide are described. (C) Pesticide Science Society of Japan