反应详情

130 g of lactic acid/glycolic acid copolymer having a weight-average molecular weight of about 5,000, (lactic acid/glycolic acid=50/50 (mol %)) was dissolved in 1,900 ml of dichloromethane; this solution was stirred and cooled. While the solution was ice cooled, the above-described diazoethane solution was added dropwise, followed by stirring at room temperature for 2 hours. After the solution was kept standing overnight, the solvent was distilled off under reduced pressure; the residue was vacuum dried at room temperature to yield 131 g of the ethyl ester of lactic acid/glycolic acid.

1. temperaturecooled
2. temperaturecooled
3. stirringby stirring at room temperature for 2 hours
4. distillationthe solvent was distilled off under reduced pressure
5. customdried at room temperature