Preparation of O,O-dimehyl phosphoramidothioate and O,O-dimethyl phosphoroamidothioate. A process of making O,O-dimethyl phosphoroamidothioate is described including reacting sulfur with PCl3to form PSCl3, reacting the PSCl3formed with methanol to form O-methyl phosphorodichloridothioate, and reacting the O-methyl phosphorodichloridothioate formed with methyl lye to form O,O-dimethyl phosphorochloridothioate in solution in CH2Cl2, and reacting the O,O-dimethyl phosphorochloridothioate formed with sodium hydroxide and ammonium hydroxide to form O,O-dimethyl phosphoroamidothioate in solution in CH2Cl2. Reacting the O,O-dimethyl phosphoroamidothioate formed with catalytic dimethyl sulfate to form methamidophos, and reacting the methamidophos formed with acetic anhydride to form N- (methoxy-methylsulfanylphosphoryl) acetamide is also described. Throughout the process, the O,O-dimethyl phosphorochloridothioate and the O,O-dimethyl phosphoroamidothioate formed are maintained in solution in CH2Cl2at all times.O,O-二甲基硫代磷醯酯的製備以及O,O-二甲基硫代磷醯酯。描述了一種製備O,O-二甲基硫代磷醯酯的方法，包括：使硫與PCl3反應以形成PSCl3；使形成之PSCl3與甲醇反應以形成O-甲基硫代磷醯二氯；使形成之O-甲基硫代磷醯二氯與甲基鹼液反應以在CH2Cl2溶液中形成O,O-二甲基硫代磷醯氯；以及使形成之O,O-二甲基硫代磷醯氯與氫氧化鈉和氫氧化銨反應以在CH2Cl2溶液中形成O,O-二甲基硫代磷醯酯。描述了使形成之O,O-二甲基硫代磷醯酯與催化硫酸二甲酯反應以形成甲胺磷，以及使形成之甲胺磷與乙酸酐反應以形成N-（甲氧基 - 甲基硫烷基磷醯基）乙醯胺。在整個過程中，形成之O,O-二甲基硫代磷醯氯和O,O-二甲基硫代磷醯酯在整個過程中始終保持在CH2Cl2溶液中。
