To a solution of 3-tert-butoxycarbonylamino-propionic acid (0.77 g, 4.09 mmol) in DMF (8.2 mL) at ambient temperature was added [1,2,3]triazolo[4,5-b]pyridin-3-ol (HOAT) (0.53 g, 3.89 mmol), EDC (0.82 g, 4.30 mmol), and 4-methylmorpholine (0.41 g, 4.09 mmol), followed by (+)-4-[1-amino-1-(3-methyl-3H-imidazol-4-yl)-ethyl]-2-fluoro-benzonitrile (Example 1, Step I) (1.00 g, 4.09 mmol). After stirring overnight, the reaction was concentrated in vacuo to remove the DMF. The residue was partitioned between EtOAc and saturated aqueous NaHCO3 solution, the organic layer washed with brine, dried (Na2SO4), and concentrated in vacuo to provide the crude title compound.
