(5 mL/mmol), and TFA (5 mL/mmol) was added. The mixture was stirred at rt for 2 h, and then concentrated under high vacuum. The deprotected amine was dissolved in anhydrous DMF (5 mL/mmol), and the appropriate acid (1 equiv) was added. DIPEA (4 equiv) was added, followed by the addition of HATU (1.1 equiv) after 5 min. The mixture was stirred at rt for 18 h, after which H2O (50 mL/mmol) was added, and extracted with EtOAc (3 × 25 mL/mmol).