Sulfuric Acid → (S)-3-amino-2-benzenesulfonylamino-propionic acid tert-butyl ester hydrochloride

HRID 265883

Reaction equation

[C:1]1([S:7]([NH:10][C@@H:11]([CH2:15][NH2:16])[C:12]([OH:14])=[O:13])(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.OS(O)(=O)=O.[CH3:22][C:23](=[CH2:25])[CH3:24].[ClH:26].CCOCC>C(Cl)(Cl)Cl.COCCOC>[ClH:26].[C:1]1([S:7]([NH:10][C@@H:11]([CH2:15][NH2:16])[C:12]([O:14][C:23]([CH3:25])([CH3:24])[CH3:22])=[O:13])(=[O:8])=[O:9])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

Conditions

Temperature: -78 °C

Procedure

In a Fischer-Porter tube, a mixture of 19-2 (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 with isobutylene (75 mL). The cooling bath was removed. After 2 h, ice/water (250 mL) was added followed by washing with ether (2×). The aqueous phase was basified with aq 6N NaOH, saturated with NaCl, and extracted with EtOAc (3×). The combined extracts were washed with brine, dried (MgSO4), and concentrated to give a white solid. This was dissolved in CHCl3 then treated with 1N HCl/ether (22 mL) then concentrated to give 19-2a as a glossy yellow solid.

Workup

customThe cooling bath was removed
additionice/water (250 mL) was added
washby washing with ether (2×)
extractionextracted with EtOAc (3×)
washThe combined extracts were washed with brine
dry with materialdried (MgSO4)
concentrationconcentrated
customto give a white solid
concentrationthen concentrated

Sources & evidence

ORD record: ord-172dcbb713a2411cb51f914afcaa051a
Source dataset: uspto-grants-1997_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05648368

Linked notes

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