反应详情

To a solution of (R)-2-cyano-1-ethylethylammonium methanesulfonate (50 mmol; 9.72 g) and DIPEA (105 mmol; 13.6 g) in dichloromethane (100 mL) is added isopropyl chloroformate (52.5 mmol; 6.43 g) at 0° C. The solution is warmed to room temperature and stirred for 4 hours. The reaction mixture is quenched with brine and extracted with dichloromethane. The organic layer is washed with aqueous 0.1M HCl, saturated aqueous NaHCO3 solution and then brine, dried over MgSO4, filtered concentrated under reduced pressure to give ((R)-2-cyano-1-ethyl-ethyl)-carbamic acid isopropyl ester (8.75 g, 95%); ESI-MS m/z: 185 [M++1], Retention time 1.60 min (condition A).

1. customThe reaction mixture is quenched with brine
2. extractionextracted with dichloromethane
3. washThe organic layer is washed with aqueous 0.1M HCl, saturated aqueous NaHCO3 solution
4. dry with materialbrine, dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure