Quantitative structure-activity analysis of larvicidal 1-(substituted benzoyl)-2-benzoyl-1-tert-butylhydrazines againstChilo suppressalis
摘要:
AbstractThe larvicidal activity of a number of 1‐(substituted benzoyl)‐2‐benzoyl–1 ‐ten‐butylhydrazines against the rice stem borer (Chilo suppressalis Walk.) was measured. Variations in the activity were examined quantitatively using physico‐chemical substituent and molecular parameters and regression analysis. The results indicated that the molecular hydrophobicity and the electron‐withdrawing inductive/ field effect of ontho substituents are favourable to larvicidal activity. The bulkiness of substituents at the meta and para positions was unfavourable to activity, substitution at the para position being more unfavourable than that at the meta position in terms of van der Waals' volume. The 2,3–, 2,5‐ and 2,6‐disubstitution patterns were also unfavourable to activity. Reductions in larvicidal activity caused by the 2,6‐,‐ 2,3,5‐ and 2,3,4,5‐substitutions were greater than those induced by the 2,3‐ and 2,5‐disubstitutions. When the sum of contributions from favourable effects is greater than that from unfavourable effects, the larvicidal activity is expected to be superior to that of the unsubstituted compound.
A compound having the formula ##STR1## wherein R.sub.1 represents halogen or methyl; R.sub.2 represents hydrogen or halogen; each of R.sub.3 and R.sub.4 represents halogen; and each of X and Y represents oxygen or sulfur. The compound is useful as insecticide.
一种化合物的化学式为##STR1## 其中 R.sub.1 代表卤素或甲基; R.sub.2 代表氢或卤素; R.sub.3 和 R.sub.4 中的每一个代表卤素; X 和 Y 中的每一个代表氧或硫。该化合物可用作杀虫剂。