反应详情

温度

-10 °C

220 g (5.5 mol) of sodium hydroxide are dissolved in 300 g of water and 700 g of ice in a 3-liter reactor having a stirrer and a cooling system. The sodium hydroxide solution is cooled to 10° C. and 526 g (5.0 mol) of aminoacetaldehyde dimethylacetal and 50 mg of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxide (radical inhibitor) are added. 548.6 g (5.5 mol) of methacrylic acid chloride are slowly added at 10° C. to the solution over a period of 3.5 hours. When the addition is complete, the pH value drops slowly to 7.2 and amine can no longer be detected by GC. The reaction mixture is extracted with 500 ml of petroleum ether, and in order to remove impurities, the aqueous phase is saturated with sodium chloride and extracted three times with 500 ml of tert-butyl methyl ether. The organic phase is dried with magnesium sulfate, filtered and concentrated using a rotary evaporator. The resulting 882.2 g of yellowish oil are slowly stirred into 2000 ml of petroleum ether at −10° C. by means of an Ultraturax. The product crystallises, and is isolated by filtration and dried. 713.8 g of methacrylamidoacetaldehyde dimethylacetal (86% of theory), melting point 30-32° C., are obtained; the product is 99.7% according to GC.

1. additionWhen the addition
2. extractionThe reaction mixture is extracted with 500 ml of petroleum ether
3. customin order to remove impurities
4. extractionextracted three times with 500 ml of tert-butyl methyl ether
5. dry with materialThe organic phase is dried with magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customa rotary evaporator
9. customThe product crystallises
10. customis isolated by filtration
11. customdried