N. Oikawa, Y. Nakagawa, K. Nishimura
Feb 1, 1994
Citations
0
Influential Citations
55
Citations
Journal
Pesticide Biochemistry and Physiology
Abstract
Abstract The larvicidal activity of 1- tert -butyl-1-(2-chlorobenzoyl)-2-(substituted benzoyl)hydrazines was measured against the rice stem borer ( Chilo suppressalis) in the presence of piperonyl butoxide, an inhibitor of oxidative metabolism. Variations in the activity were quantitatively examined by use of physicochemical substituent parameters and regression analysis. The results indicated that the hydrophobicity of substituents is favorable in general but the bulkiness of substituents is unfavorable position-specifically. The most favorable substitution pattern is the para substitution with lower alkyls and halogens. Compounds in which substitution patterns are simultaneously optimized in two benzene rings in the molecule were designed and prepared according to the present and previous quantitative analyses. Some of them, including 1- tert -butyl-1-(3,5-dichloro- and 3,5-dimethylbenzoyl)-2-(4-ethylbenzoyl)hydrazines, the second being RH-5992, were about 20-30 times as larvicidal as the unsubstituted compound, RH-5849, against the rice stem borer.