PROCESS FOR THE MANUFACTURE OF N(MERCAPTOMETHYL) PHTHALIMIDE S-(O,O-DIMETHYL PHOSPHORODITHIOATE

Process for preparing s- (0,0-dimethyl-phosphorodithioate) of n (mercaptomethyl) phthalimide, characterized in that it comprises the steps of: A) forming a mixture of N-hydroxymethylphthalimide, an organic solvent in the amount of 378 to 672 liters of said solvent per kilolol of N-hydroxymethylphthalimide, and 210 to 420 liters of an aqueous solution of hcl at 35-40% by weight per kilomol of N-hydroxymethylphthalimide; B) reacting said mixture, at a temperature of about 45 to 75ºC and a pressure of about 0 to 3.5 kg/cm2, while the reaction mixture is in intimate contact with anhydrous hcl, at a rate of 15 to 65 kg approximately of hcl per hour per kilolol of N-hydroxymethylphthalimide used to form the mixture in step a), to maintain the concentration of aqueous hcl at a level of 35 to 40% by weight, to form N-chloromethylphthalimide in a first mixture aqueous-organic; C) separating the organic phase having dissolved in the same N-chloromethylphthalimide, from said first aqueous-organic mixture; D) forming a second mixture of said separate organic phase having N-chloromethylphthalimide dissolved therein from step c) and a further amount of organic solvent, so that the total amounts of solvent added at this stage and at the step a) amount to 672-1,092 liters of said solvent per kilolol of N-hydroxymethylphthalimide used to form the mixture in step a), and sodium 0.0-dimethyldithiophosphate in a molar amount equal to about 110-150% of the molar amount of N-hydroxymethylphthalimide used to form the mixture in step a); E) reacting the second mixture, at a temperature of approximately 45 to 70ºC and at a pressure ranging from the environment to approximately 0.7 kg/cm2, to form N- (mercaptomethyl) s- (0,0-dimethylphosphorodithioate) phthalimide in a second aqueous-organic mixture; F) separating the organic phase having dissolved therein said s- (0,0-dimethylphosphorodithioate) from n (mercaptomethyl) phthalimide, from said second aqueous-organic mixture; y G) recovering from the organic phase said N- (mercaptomethyl) phthalimide s- (0,0-dimethylphosphorodithioate). (Machine-translation by Google Translate, not legally binding)