Sulfuric Acid → (S)-3-amino-2-benzenesulfonylamino-propionic acid tert-butyl ester hydrochloride
Reaction equation
[NH2:1][CH2:2][C@H:3]([NH:7][S:8]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)(=[O:10])=[O:9])[C:4]([OH:6])=[O:5].OS(O)(=O)=O.[CH3:22][C:23](=[CH2:25])[CH3:24].[ClH:26].CCOCC>C(Cl)Cl.COCCOC>[ClH:26].[NH2:1][CH2:2][C@H:3]([NH:7][S:8]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)(=[O:10])=[O:9])[C:4]([O:6][C:23]([CH3:25])([CH3:24])[CH3:22])=[O:5]Participants
7
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- -78 °C
Procedure
In a Fischer-Porter tube, a mixture of 2-1b (10.2 g, 42 mmol) and DME (150 mL) was sequentially treated with H2SO4 (6.4 mL, 0.12 mol), cooled to -78° C., and then condensed isobutylene (75 mL). The tube was sealed and the cooling bath was removed. After 24 h, ice/water (250 mL) was added followed by washing with ether (2×). The aqueous phase was basified with aq 6N NaOH, then saturated with NaCl, followed by extraction with EtOAc (3×). The combined extracts were washed with brine, dried (MgSO4), and concentrated to give a white solid. This was dissolved in CH2Cl2 and treated with 1N HCl/ether (22 mL), and then concentrated to give 2-1 as a glassy yellow solid.
Workup
- customThe tube was sealed
- customthe cooling bath was removed
- additionice/water (250 mL) was added
- washby washing with ether (2×)
- extractionsaturated with NaCl, followed by extraction with EtOAc (3×)
- washThe combined extracts were washed with brine
- dry with materialdried (MgSO4)
- concentrationconcentrated
- customto give a white solid
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-94c1eed3020540858efbe5b1260ccd9c
- Source dataset
- uspto-grants-1999_07
- Patent number
- US05929120
Reaction notes
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