Abstract
A number of alkoxysulfenyl derivatives of insecticidal methylcarbamates were synthesized by the reaction between alcohols and N-chlorosulfenyl-N-methylcarbamate, the latter being prepared from the methylcarbamate and sulfur dichloride in the presence of base. Polysulfide analogs of the alkoxysulfenyl derivatives were also formed in significant amounts as byproducts by this method. The alkoxysulfenyl derivatives of phenyl carbamates proved to be stable, whereas the derivatives of oxime carbamates were unstable. All of the alkoxysulfenyl derivatized carbamates, with a few exceptions, showed high insecticidal activity against houseflies and green rice leafhoppers. Some of the derivatives of carbofuran (2, 3-dihydro-2, 2-dimethyl-7-benzofuranyl N-methylcarbamate) appeared more effective against houseflies than the parent carbofuran. Derivatization generally resulted in substantial improvement in toxicity to mice. Toxicity of the derivatives of carbofuran to mice systematically decreased with increase in carbon atoms in the straight chain alkoxy moiety. All the polysulfide analogs were insecticidal, and both the activity to houseflies and the toxicity to mice decreased with increase in the number of sulfur atoms in the molecule.
