Insecticidal Carbamates: Position Isomerism in Relation to Activity of Substituted-Phenyl N-methylcarbamates1

Abstract

The anticholinesterase activity and toxicity to three species of insects were compared for 49 phenyl N-methylcarbamates substituted in ortho-, meta- and para-positions. Maximum activity as insecticides and anticholinesterases occurred when the structures exhibited the closest complementariness to the active site of cholinesterase. This was obtained with compounds which incorporated a bulky phenyl substituent group with a large Van der Waals energy of interaction, placed at a distance of about 5 Å from the carbonyl group.