PRODUCTION OF O,O-DIMETHYL PHOSPHOROAMIDOTHIOATE

PROBLEM TO BE SOLVED: To obtain the subject compound useful as an intermediate for insecticides by reacting O,O-dimethyl phosphorochloridothioate with ammonia in the presence of an alkali hydroxide, as the amount of ammonia used can be reduced without waste water. SOLUTION: The reaction of O,O-dimethyl phosphorochloridothioate with ammonia is carried out by using 1-1.5 mole of ammonia and 0.8-1.1 mole of an alkali hydroxide, for example, sodium hydroxide, per mole of the O,O- dimethyl phosphorochloridothioate and heating up to 40 deg.C. Then, the reaction mixture is phase-separated into the oil layer and the aqueous layer, the reaction product is extracted from the aqueous layer with toluene or the like and the solvent is evaporated off from the extraction solution to give the objective compound. In this process, the reaction smoothly proceeds with a reduced amount of ammonia to form the objective compound useful as a raw material for production of insecticides without occurrence of waste water containing a large amount of ammonium chloride.