Chemical Structure and Acaricidal Activity of 3-Alkylthiophenyl 4-Nitrophenyl Ethers

Abstract

Many 4-nitro diphenylether derivatives with R-S (O)_x-substituents were systematically synthesized and their pesticidal activities were investigated. 3-n-Propylthiophenyl 4-nitro-phenyl ether and its sulfoxide analog exhibited remarkable acaricidal and chlorosis-inducing activities on the young leaves of plants. For all compounds with the substituent at the 4 position in the 3-n-propylthio (and -sulfinyl) phenyl group, chlorosis-inducing activity vanished and an acaricidal activity stronger than that of the parent compound appeared. Evidence that the acaricidal and chlorosis-inducing activities are greatly influenced by the size of the 4-substituent and the hydrophobicity of R in the 3-R-S (O)_x-substituent is presented.