反应详情

To a solution of 55.8 g of N-(2-methoxyethyl)glycine tert-butyl ester in 200 ml of benzene was added 63.8 g of benzyl alcohol and 72.9 g of p-toluenesulfonic acid monohydrate. The mixture was heated at reflux for 10 hours with the continuous removal of water through a Dean-Stark water trap. At the end of this period, the solution was concentrated in vacuo, and to the residue was added 300 ml of dry ethyl ether. After 2 hours at room temperature, the formed precipitate was filtered, washed with dry ethyl ether and then recrystallized from ethyl acetate to yield 99.2 g (85 percent) of N-(2-methoxyethyl)glycine benzyl ester p-toluenesulfonate, M.P. 95°-96° C.

1. temperatureThe mixture was heated
2. concentrationAt the end of this period, the solution was concentrated in vacuo
3. additionto the residue was added 300 ml of dry ethyl ether
4. filtrationthe formed precipitate was filtered
5. washwashed with dry ethyl ether
6. customrecrystallized from ethyl acetate