2-(7-Aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU) (3.1 mmol) was added to a suspension of 3-bromo-1-trityl-1H-indazole-5-carboxylic acid (1 g, 2.07 mmol) in DMF (5 mL) and was stirred at room temperature for 15 minutes. A solution of (R)-benzyl 3-aminopiperidine-1-carboxylate (500 mg, 2.13 mmol) in DMF (5 mL) was added to the reaction and followed by diisopropyl ethyl amine (DIEA) (0.72 mL). The mixture was stirred at room temperature for an additional 30 minutes. The reaction was quenched with water (50 mL) and extracted with ethyl acetate (3×100 mL). The extracts were combined, dried using anhydrous sodium sulfate, filtered, and concentrated in vacuo. The crude product was progressed to the next step without purification.
