Method for synthesizing pesticide Silthiopham

The invention belongs to the technical field of organic synthesis and provides a method for synthesizing a pesticide Silthiopham. The method is used for solving the problem of the pesticide Silthiopham synthesis process at present that the yield of exchange reaction is low. The method comprises the steps of (1) enabling trimethylsilyl acetylene, which serves as a raw material, to react with methyl chloroformate in the presence of an organic base under the protection of inert gas so as to obtain trimethylsilyl methyl propiolate; (2) enabling trimethylsilyl methyl propiolate to react with 3-mercapto-2-butanone in the presence of a basic catalyst so as to obtain 4,5-dimethyl-2-(trimethylsilyl)thiophen-3-methyl formate; and (3) enabling 4,5-dimethyl-2-(trimethylsilyl)thiophen-3-methyl formate to react with allyl amine in the presence of a catalyst, thereby obtaining the end product pesticide Silthiopham. According to the method, the used raw materials are cheap and readily-available, the route is simple, the overall yield is relatively high, and the consumption of reagents causing serious environmental pollution such as tert-butyl nitrous acid (t-BuONO) and thionyl chloride is avoided.