Formic Acid → Aldicarb sulfone

Participants

Reaction Conditions

Reaction Steps

15 grams of an 88 percent aqueous solution of formic acid was added to a mixture containing 30 grams of 2-methyl-2-(methylthio)propionaldehyde O-(methylcarbamoyl)oxime in 70 grams of methylene chloride solution. To the mixture was added 56 grams of a 30 percent aqueous hydrogen peroxide over a 15-20 minute period. During the course of addition, the reaction temperature rose from 25° to 40° C. with a gentle reflux of methylene chloride. After the addition of the peroxide solution, 6.0 grams of concentrated sulfuric acid was added dropwise at a rate to maintain the reflux at 40° C. When the addition was complete, the mixture was stirred for an additional 2.5 hours at 40.45° C. When the oxidation was over, 60-70 grams of the methylene chloride solvent was removed by evaporation under reduced pressure. The mixture was cooled to 5° C. and filtered. The solid reaction product was then washed with 25-30 grams of cold water and dried to constant weight. (2-Methyl-2-(Methylsulfonyl)propionaldehyde O-(methylcarbamoyl)oxime was obtained, m.p. 144°-145° C, having a 2-methyl-2-(methylsulfinyl)propionaldehyde O-(methylcarbamoyloxime (sulfide) content of less than 0.10 percent.

Provenance & Evidence