反应详情

2 g of maleimide-styrene copolymer are dissolved in 25 ml of DMF, 3 g of triphenylphosphine and 1.8 ml of ethyl azodicarboxylate are added, and the mixture is stirred for 15 minutes, during which slight warming occurs. 1.5 ml of L-(-)-butyl lactate are then added, and the mixture is stirred at room temperature for 20 hours, giving a clear, red-brown solution, which is poured into 300 ml of methanol. A milky-white precipitation of the polymer is obtained. Since the substance has a tacky consistency, it is separated off by centrifugation. After repeated washing with methanol and centrifugation, the product is dried at 70° C. in a drying cabinet. Yield 2.5 g. The polymer exhibits a rotation value of [α]D20 =+6.7° in the DMF solution.

1. temperatureslight warming
2. stirringthe mixture is stirred at room temperature for 20 hours
3. customgiving a clear, red-brown solution, which
4. customA milky-white precipitation of the polymer
5. customis obtained
6. customis separated off by centrifugation
7. washAfter repeated washing with methanol and centrifugation
8. customthe product is dried at 70° C. in a drying cabinet
9. customa rotation value of [α]D20 =+6.7°