tert-Butyl [(1R)-2-(3-amino-4-nitrophenoxy)-1-phenylethyl]carbamate (Intermediate 5) (346 mg, 0.93 mmol) was placed in a microwave reaction vial (10-20 mL), followed by iron (259 mg, 4.63 mmol), water (4 mL), ammonium chloride (40 mg, 0.74 mmol) and finally ethanol (4 mL). The reaction vial was sealed, and set to heat at 80° C. for twenty hours. The reaction was added to a separatory funnel containing ethyl acetate (100 mL) and brine (75 mL); the phases were separated, and the organic layer was washed again with brine (75 mL). The ethyl acetate layer was then concentrated in vacuo to afford tert-butyl [(1R)-2-(3,4-diaminophenoxy)-1-phenylethyl]carbamate as an orange solid. LRMS (ESI) cale'd for (C19H26N3O3) [M+H]+, 344.2; found 344.2.
