Dialkyl phosphorochloridothioates

Methyl parathion was developed around 1948 when the German technology was discovered after the war. Parathion (the ethyl analog) is not so safe and is used to a lesser extent. Both methyl parathion and parathion are synthesized by reacting the sodium salt of p-nitrophenol with 0,0-dialkyl phosphorochloridothioate, which is made from phosphorus pentasulfide, the alcohol, and chlorine. 

Dialkyl phosphorochloridothioates are intermediate products in the preparation of most compounds of a phosphorothioate ester base. 

Dialkyl phosphorochloridothioates, important as intermediates for insecticide manufacture, are made by reaction (12.93), but care has to be taken to avoid other products (9.369). 

A series of 0,0-dialkyl-0-2-pyrazinylphosphorothioates and related compounds have been prepared and tested as pesticides. Thionazin (15), the product of reaction of the sodium salt (159) and 0,0-diethyl-phosphorochloridothioate (160) is used in agriculture.360-364... 

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