Synthesis and Biological Activity of 0, 0-Dialkyl S-(5-Aryl-1, 3, 4-oxadiazol-2(3H)-on-3-yl)methyl Phosphorothioates and Phosphorodithioates

Abstract

Some phosphorus derivatives of oxadiazoles were synthesized to seek insecticidal lead compounds. The 1, 3, 4-oxadiazol-2-ones were converted via the N-methylol derivatives to the corresponding N-chloromethyl derivatives. From these derivatives a variety of 0, 0-dimethyl phosphorodithioates 4, 0, 0-dimethyl phosphorothioates 5 and 0, 0-di-i-propyl phosphorothioates 6 were prepared.
These phosphorus derivatives were examined for insecticidal activity towards houseflies and for anti-acetylcholinesterase (anti-AChE) activity using the housefly heads as an enzyme source. Most of the compounds 4 and 5 showed contact toxicity as high as the analogous methidathion insecticides, which appeared to correlate with the strong anti-AChE activity. On the other hand, all the compounds 6 showed a high activity in AchE inhibition but only a poor insecticidal activity.