反应详情

温度

5 °C

55 grams of a 30 percent aqueous hydrogen peroxide solution was added dropwise to a mixture of 55 grams of 2-methyl-2-(methylthio)propionaldehyde O-(methylcarbamoyl)oxime and 15 grams of formic acid in 200 grams of methylene chloride solution over a 15-20 minute period. The temperature rose from 25° to 40° C. during the addition. When the addition was complete 3 grams of concentrated sulfuric acid was added dropwise to maintain a gentle reflux followed by an additional 2 hours of reflux at 40°-45° C. After the reaction period was over, methylene chloride solvent was evaporated under reduced pressure. The mixture was cooled to 5° C. and filtered. The 2-methyl-2-(methylsulfonyl)propionaldehyde solid obtained was washed with 200 ml of water and dried to give 37 grams 2-methyl-2-(methylsulfonyl)propionaldehyde O-(methylcarbamoyl)oxime m.p. 145°-147° C. The yield was 90.5 percent based on 2-methyl-2-(methylthio)propionaldehyde.

1. additionThe temperature rose from 25° to 40° C. during the addition
2. additionWhen the addition
3. additionwas added dropwise
4. temperatureto maintain
5. temperaturea gentle reflux
6. temperatureof reflux at 40°-45° C
7. customAfter the reaction period
8. customwas evaporated under reduced pressure
9. filtrationfiltered