Abstract
Twenty O, O-dialkyl-O-(2-benzyl-3-oxo-2 H-pyridazine-6-yl) phosphorothioates (III) were pre-pared. Their insecticidal activities against rice plant pests, including the two-spotted spider mite, and their toxicity to mice and small killifishes were studied. Of compounds tested, O, O-dimethyl-O-[2-(2-methylbenzyl)-3-oxo-2H-pyridazine-6-yl]phosphorothioate (III-2) was the most effective against rice plant pests, including the two-spotted spider mite, and it showed low toxicity to mice and small killifishes. The relationships between chemical structure, activity and toxicity were examined.
