Ammonium Chloride → (R)-benzyl 2,2-dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]thiazepin-3-ylcarbamate

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Reaction Steps

DIEA (4.14 g, 5.6 mL, 32.0 mmol, Eq: 2) and (benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyBOP, 12.5 g, 24.0 mmol, Eq: 1.5) were added to (R)-3-(2-aminophenylthio)-2-(benzyloxycarbonylamino)-3-methylbutanoic acid (6 g, 16.0 mmol, Eq: 1.00) in DMF (200 mL). The mixture was stirred at RT overnight then heated to 80° C. for 3 h. The mixture was poured onto sat. NH4Cl and extracted with EtOAc. The combined extracts were washed with H2O, concentrated and the residue was purified by silica gel chromatography to give (R)-benzyl 2,2-dimethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]thiazepin-3-ylcarbamate (3 g, 52%).

Provenance & Evidence