Methamidophos → Acephate

Participants

Reaction Steps

19.1 Grams of dimethyl sulfate were gradually added to 296 g (purity 86.3%) of O,O-dimethylphosphoramidothioate at 40° C. in 30 min and to the resultant were further added 1180 g of O,O-dimethyl phosphoramidothioate and 76.1 g of dimethyl sulfate at the same temperature over 2 hours separately. The resultant reaction mixture was further maintained at the temperature for 8 hours to obtain 1562 g of O,S-dimethyl phosphoramidothioate(purity: 79.1%). To 1562 g of obtained O,S-dimethyl phosphoramidothioate was added 1218 g of acetic anhydride and 41 g of dimethyl sulfate at 40° C. over an hour. The resultant was maintained at the temperature for an hour to complete the reaction to give 2799 g of crude O,S-dimethyl N-acetylphosphoramidothioate (purity: 49.13%).

Provenance & Evidence