QSAR AND MOLECULAR SHAPE ANALYSES OF 3 SERIES OF 1-(PHENYLCARBAMOYL)-2-PYRAZOLINE INSECTICIDES

Three structurally related series of 1-(phenylcarbamoyl)-2-pyrazolines that exhibit insecticidal activity have been studied in terms of mole cular shape and QSAR analyses. The active conformation, in terms of N- 1-phenylamide and C-3-phenyl ring substituents to the pyrazoline ring, could be postulated. The bioactive conformation corresponds to a near all-planar structure. No bioactive conformation could be postulated f or phenyl rings on either of the saturated carbons of the pyrazoline r ing. However, for C-4-phenyl ring substitution, the only stable confor mation corresponds to the plane of the phenyl ring being nearly perpen dicular to the plane of pyrazoline ring. Dipole moment properties of t he substituted phenylamide unit to the N-1 of the pyrazoline ring corr elate with insecticidal potency. Lipophilicity is not found to be impo rtant in dictating insecticidal activity.