反应详情

温度

60 °C

A 250-mL round bottom flask was charged with (2R)-1,4-bis(tert-butoxycarbonyl)-2-piperazinecarboxylic acid (10.5 g, 31.8 mmol, ASW Medchem, New Brunswick, N.J.) under nitrogen. THF (20 mL) was added and the mixture was cooled in an ice bath. A solution of BH3.THF (1M in THF, 65 mL, 65.0 mmol, Sigma-Aldrich) was added over 10 min. The ice bath was removed and after 15 min, the flask was equipped with a reflux condenser and was the reaction was heated at 60° C. After 1.5 h, the mixture was cooled in an ice bath and was then quenched with MeOH (10 mL, 247 mmol) over 20 min. The mixture was concentrated, treated with MeOH (20 mL), and concentrated a second time to give di-tert-butyl (2R)-2-(hydroxymethyl)-1,4-piperazinedicarboxylate as a white solid (10 g).

1. temperaturethe mixture was cooled in an ice bath
2. customThe ice bath was removed and after 15 min
3. customthe flask was equipped with a reflux condenser
4. temperaturethe mixture was cooled in an ice bath
5. concentrationThe mixture was concentrated
6. additiontreated with MeOH (20 mL)
7. concentrationconcentrated a second time