Trifluoroacetic acid → (S)-2-Amino-3-(4-nitrophenyl)propan-1-ol

Participants

Reaction Steps

TFA (171 mL) was added to a solution of (S)-tert-butyl-1-hydroxy-3-(4-nitrophenyl)propan-2-ylcarbamate 20 (Erlanson et al., U.S. Pat. No. 7,214,487 B2; 13.9 g, 46.9 mmol) in DCM (272 mL) at 0° C. The reaction mixture was warmed to RT and reaction was allowed to proceed for 25 minutes. The solution was concentrated to afford 9.2 g of crude (S)-2-amino-3-(4-nitrophenyl)propan-1-ol as a white solid. To a solution of this crude product and sodium carbonate (12.4 g, 117.3 mmol) in THF (87 mL) and water (87 mL) was added N-carbethoxyphthalimide (“CEPT,” 12.3 g, 56.3 mmol). After the reaction mixture was stirred at RT for 4 h, EtOAc (150 mL) was added. The aqueous phase was extracted with EtOAc. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated under vacuum to give a crude residue which was purified by flash chromatography eluting from silica gel with a gradient of 0-100% EtOAc in hexanes to give 12.3 g of alcohol 30. MS: (+) m/z 327.0 (M+1).

Provenance & Evidence