Abstract: A series of new silicon-containing carbamate derivatives 3 have been prepared from reaction of 1-methylthio-ethylideneamino-methyl carbamate (Methomyl) 1 with thionyl chloride. Their structures were confirmed by ¹H NMR,elemental analysis,IR and MS. The crystal structure of compound 3a was determined by X-ray diffraction method.The bioassay results showed that compound 3 have a high insecticidal activity against mosquito,armyworm, European corn borer, flour beetle and cowpea aphid and a substantial improvement in acute mammalian safety toward male and female mice when compared to that of parent Methomyl.

Key words: carbamates, silicon derivative, biological activity