Quantitative Structure-Activity Relationships of Insecticidal Pyrazolines

Article abstract of DOI:10.1002/ps.2780420406

Methyl 3-(4-chlorophenyl)-4-methyl-1--2-pyrazoline-4-carboxylates and related compounds were prepared. Their convulsant activity was determined as the minimum dose required to bring about the symptom within 1 h after injection against male adult American cockroaches, Periplaneta americana (L.). Insecticidal activity with metabolic inhibitors for oxidation and hydrolysis was measured 24 h after injection of the test compounds. Variations in each of the activities were analysed by using physicochemical substituent parameters and regression analysis. The findings indicated that the greater the hydrophobicity and the more the electron-withdrawing property of the substituents, the higher were the activities. Variations in each of the two activities were parabolically related to the STERIMOL width parameter with an optimum value of about zero.