(S)-tert-Butoxycarbonylamino-phenyl-acetic acid (1.00 g, 4 mmol) was dissolved in DCM (15 mL). Benzylamine (0.428 g, 4 mmol) and DIEA (0.65 g, 5 mmol) were added to the above mixture. The mixture which resulted was stirred at room temperature for a few minutes. PyBroP (2.10 g, 4.5 mmol) was added to the above solution in one portion and the reaction mixture was stirred overnight. The reaction mixture was diluted with DCM (150 mL) and washed with NaHCO3 (50 mL×2, sat.). The organic layer was collected and dried (Na2SO4) and the solvent was removed under reduced pressure. The crude product was purified by chromatography to provide the desired product (0.859, 62%).
