Bayer Corporation

Scott P Hensley

Vidyanatha A Prasad

Klaus Jelich

Donald Smith

Stephen C Slahck

Jonathan D Spicher

Christopher M Tusa

Daniel E Terry

David L Meyer

The present invention provides a continuous process for making O,O-dimethyl phosphoroamidothioate. In accordance with this process, O,O-dimethyl phosphorochloridothioate is reacted with ammonia and sodium hydroxide; addition of the sodium hydroxide controls the pH of the reaction mixture. The formed reaction mixture contains an aqueous phase and an organic phase. The organic phase of the reaction mixture is separated from the aqueous phase; a second organic phase is solvent extracted from the aqueous phase; and the resultant O,O-dimethyl phosphoroamidothioate is isolated from the combined organic phases via vacuum solvent stripping. In an embodiment of the present invention, the reaction of O,O-dimethyl phosphorochloridothioate with ammonia and sodium hydroxide is carried out in the presence of a solvent.

Process for the synthesis of O,O-dimethyl phosphoroamidothioate

The present invention relates to an integrated process for synthesizing dimethyl (2,2,2-trichloro-1-hydroxyethyl)-phosphonate and a process for impregnating the dimethyl (2,2,2-trichloro-1-hydroxyethyl)-phosphonate on to inert carrier granules. The process involves adding dimethyl phosphite to a reaction mixture containing chloral under anhydrous, inert conditions. The molar ratio of chloral to dimethyl phosphite used in the reaction mixture is from about 1.0:1.0 to about 1.1:1.0. The impregnation process involves transferring molten dimethyl (2,2,2-trichloro-1-hydroxyethyl)-phosphonate into a process vessel and discharging weighed aliquots into a formulation vessel to form a granular product containing dimethyl (2,2,2-trichloro-1-hydroxyethyl)-phosphonate.

Process for producing dimethyl

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Kansas City, MO, United States of America

Scott P Hensley