Benzyl chloroformate → (S)-1-((Benzyloxy)carbonyl)-4-(tert-butoxycarbonyl)piperazine-2-carboxylic acid
Reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][C@H:10]([C:14]([OH:16])=[O:15])[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C([O-])(O)=O.[Na+].[C:22](Cl)([O:24][CH2:25][C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)=[O:23]>O.O1CCOCC1>[CH2:25]([O:24][C:22]([N:11]1[CH2:12][CH2:13][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[CH2:9][C@H:10]1[C:14]([OH:16])=[O:15])=[O:23])[C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
To a stirred suspension of (S)-4-(tert-butoxycarbonyl) piperazine-2-carboxylic acid (1.0 g, 4.34 mmol) in water (5 mL) was added solid NaHCO3 (0.73 g, 8.68 mmol) at room temperature. The reaction mixture was stirred at room temperature to get clear solution. Solution of CBZ-Cl (1.22 mL, 8.68 mmol) in 1,4-dioxane (10 mL) was added dropwise and the reaction mixture was stirred at room temperature for 16 h. The reaction mixture was diluted with water (20 mL) and extracted with EtOAc (2×20 mL). The aqueous layer was acidified with 0.5M aqueous HCl to pH 5 and extracted with EtOAc (2×50 mL). The combined organic layers were dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to afford the title compound (1.30 g) as white solid.
Workup
- customto get clear solution
- stirringthe reaction mixture was stirred at room temperature for 16 h
- extractionextracted with EtOAc (2×20 mL)
- extractionextracted with EtOAc (2×50 mL)
- dry with materialThe combined organic layers were dried over anhydrous Na2SO4
- filtrationfiltered
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-e7a13e2c7d654335b20d2f7beaa2e0a2
- Source dataset
- uspto-grants-2015_09
- Patent number
- US09133147B2
Reaction notes
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