| Name | Phosphorus-containing intermediates of asymmetric organophosphorus pesticides |
| Synonyms | Phosphorus-containing intermediates of asymmetric organophosphorus pesticides |
After the 1970s, the focus of foreign research on organophosphorus pesticides has gradually shifted to asymmetric compounds centered on phosphorus atoms, and some of the more mature varieties have been commercialized. From the synthesis process, many new varieties containing asymmetric phosphorus atoms are synthesized by O-alkyl thiophosphoryl dichloride (dichloride) and O-alkyl-S-alkyl (II) thiophosphoryl chloride.
Dichloride is generally obtained by the reaction of thiophos trichloride and alcohol. This reaction is easy to proceed, and a higher yield and content are obtained. Then replace the two chlorides of dichloride with amino group and alkoxy group (or aryloxy group) respectively to obtain thiophosphoramide compounds, such as insecticides isocarbophos, methyl isophanate, herbicide Amine phosphorus, grass phosphorus suppression, etc. Synthesis of thiophosphoramide pesticides from dichloride
Starting from O-alkyl-S-alkyl (II) thiophosphoryl chloride, through a series of reactions, various asymmetric (II) thiophosphate pesticides can be synthesized, such as profenofos, methyl propylsulfur, propylsulfur, etc.