反应详情

A 20-mL vial was charged with ((2R)-1,4-bis(tert-butoxycarbonyl)-2-piperazinecarboxylic acid (1.57 g, 4.76 mmol, ASW MedChem Inc., New Brunswick, N.J.), HATU (2.17 g, 5.72 mmol, ChemImpex International Inc., Wood Dale, Ill.), propan-2-amine (0.450 mL, 5.28 mmol, Sigma-Aldrich, St. Louis, Mo.), DIPEA (1.70 mL, 9.76 mmol) and DMF (8 mL). The mixture was stirred at room temperature for 2.5 h. The reaction mixture was partitioned between water (80 mL) and EtOAc (50 mL). The aqueous phase was extracted with EtOAc (50 mL). and the combined organic phases were washed with saturated aqueous NaHCO3 (100 mL), water (100 mL), then brine (100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to afford di-tert-butyl (2R)-2-((1-methylethyl)carbamoyl)-1,4-piperazinedicarboxylate (2.30 g) as a light-brown foam.

1. customThe reaction mixture was partitioned between water (80 mL) and EtOAc (50 mL)
2. extractionThe aqueous phase was extracted with EtOAc (50 mL)
3. washand the combined organic phases were washed with saturated aqueous NaHCO3 (100 mL), water (100 mL)
4. dry with materialbrine (100 mL), dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo