Inventors:
Jack J. Lonsinger - Liberty MO
Chester W. Halbleib - Holt MO
Assignee:
Mobay Chemical Corporation - Kansas City MO
International Classification:
C07F 924
Abstract:
In the isomerization of an O,O-dialkyl phosphoroamidothioate to an O,S-dialkyl phosphoroamidothioate by heating the O,O-dialkyl starting material in the presence of a catalyst, followed by recovery of the desired O,S-dialkyl end product, the improvement which comprises arresting the heating when about 40 to 70% of the O,O-dialkyl starting material has isomerized to O,S-dialkyl product, separating unreacted O,O-dialkyl starting material from the O,S-dialkyl isomerization product, and further treating the O,O-dialkyl starting material to effect further isomerization. The separation is effected either by cooling to crystallize out O,S-dialkyl isomer or by evaporating off the O,O-dialkyl starting material.