Synthesis and insecticidal evaluation of N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐diacylhydrazines

A series of novel N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐diacylhydrazines were synthesized by the reaction of chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] with N‐tert‐butyl‐N,N′‐diacylhydrazine in the presence of sodium hydride. The reaction of sulfur dichloride with O‐(1‐methylthioethylimino)‐N‐methylcarbamate (Methomyl) in the presence of pyridine to yield chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] was reported for the first time. X‐ray single crystal diffraction of N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐dibenzoylhydrazine demonstrated that the parent compounds N‐tert‐butyl‐N,N′‐dibenzoylhydrazine and O‐(1‐methylthioethylimino)‐N‐methylcarbamate were combined by N S N band to give the product. Their larvicidal activities against Oriental armyworm and Aphis laburni were evaluated. All of them exhibited excellent larvicidal activities against Oriental armyworm, with some of them showing higher larvicidal activities than the parent diacylhydrazines. Toxicity assays indicated that the products show knockdown activity for O‐(1‐methylthioethylimino)‐N‐methylcarbamate at higher concentration and insect growth regulators' activities of diacylhydrazines at lower concentrations. At the same time, the products possess insecticidal activities against the aphids. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:631–636, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20360