Dimethoate production

摘要

Process for producing dimethoate (N-methyl-2-(O,O-dimethylthiophosphorylthio)acetamide) comprises reacting methyl 2-(O,O-dimethylthiophosphorylthio)acetate (I) with an aqueous solution of methylamine in excess in a multistage reactor cascade indirectly cooled to between -2 and +2 deg C. The cascade comprises at least three stirred reactors operating cocurrently with overflow transfer equipped with peripheral anchor agitators rotating at a rate of 2.5-4.0 m/sec. The height:diameter ratio of the cylindrical part of the first reactor is 1:0.8-1.2. The ratio of the volume capacity of the first reactor to the total volume capacity of the subsequent reactors is 1:1.5-2.5. The reactors are inclined at an angle of 20-45 deg .