QUANTITATIVE STRUCTURE-ACTIVITY STUDIES OF PYRETHROIDS .31. INSECTICIDAL ACTIVITY OF META-SUBSTITUTED BENZYL-ESTERS OF 1-(PARA-ETHOXYPHENYL)-2,2-DICHLOROCYCLOPROPANE AND 2,2,3,3-TETRAFLUOROCYCLOBUTANE-1-CARBOXYLIC ACIDS

Esters of racemic para-ethoxyphenyl)-2,2,3,3-tetrafluorocyclobutane- a nd thoxyphenyl)-2,2-dichlorocyclopropane-1-carboxylic acids with a num ber of meta-substituted benzyl alcohols were prepared. Their insectici dal activity against American cockroaches was measured by injection un der synergistic conditions with inhibitors of oxidative and hydrolytic metabolic mechanisms. The insecticidal activity of the tetrafluorocyc lobutanecarboxylates was usually more potent than that of the correspo nding dichlorocyclopropanecarboxylates, although the degree was not un iform. Variations in the insecticidal potency were quantitatively exam ined using physicochemical substituent and structural parameters and r egression analyses. The introduction of substituents possessing a benz ene ring per se was favorable for the activity when factors due to phy sicochemical and steric features were equal among analogs in the two s eries of esters. The less bulky the substituents, the higher the insec ticidal potency of both series, when the effect of the benzene ring wa s separated. For F-4-cyclobutanecarboxylates, the hydrophobicity of su bstituents augmented the potency. In each series, the effect of substi tuents introduced into the phenoxy-benzene ring as the component of th e primary substituent was such that there is an optimum hydrophobicity for the interaction of this local moiety with a hypothetical receptor . The para-substituted phenoxy groups were more favorable than ortho- and meta-substituted phenoxy groups, (C) 1994 Academic PI ess, Inc.