反应详情

6 g of a lactic acid/glycolic acid copolymer having a weight-average molecular weight of about 7,500 (lactic acid/glycolic acid=75/25 (mol %)) (Wako Pure Chemical Industries, Ltd.) was dissolved in a mixed solvent consisting of 60 ml of dichloromethane and 60 ml of ethanol. While thus obtained solution was cooled and stirred, 3.83 g of 1-ethyl-3-(3-dimethylaminoisopropyl)-carbodiimide hydrochloride was added and then the reaction mixture was stirred overnight. After 50 ml of water was added, dichloromethane phase was separated. The dichloromethane phase was washed 2 times with 40 ml of 10% ethanol-water and dried with magnesium sulfate. After magnesium sulfate was separated by filtration, the mixture was concentrated to dryness under reduced pressure to yield 5.2 g of the ethyl ester of lactic acid/glycolic acid copolymer.

1. dissolutionwas dissolved in a mixed solvent
2. temperatureWhile thus obtained solution was cooled
3. stirringthe reaction mixture was stirred overnight
4. customdichloromethane phase was separated
5. washThe dichloromethane phase was washed 2 times with 40 ml of 10% ethanol-water
6. dry with materialdried with magnesium sulfate
7. customAfter magnesium sulfate was separated by filtration
8. concentrationthe mixture was concentrated to dryness under reduced pressure