A solution of compound 4 (150 mg, 0.51 mmol), 4-(aminomethyl)benzylnitrile (compound 6, 171 mg, 1.02 mmol), EDC (195 mg, 1.02 mmol), and N-hydroxybenzotriazole (78 mg, 0.51 mmol) in acetonitrile (5.1 ml) was stirred at ambient temperature for 10 minutes. 2,4,6-Collidine (0.34 ml, 2.54 mmol) was then added and the reaction mixture was stirred overnight at ambient temperature. The solvent was removed under reduced pressure and the resulting residue was resuspended in ethylacetate (100 ml) and 0.5M HCl (10 ml). The ethylacetate layer was washed with water followed by 0.5M HCl (10 ml), saturated sodium bicarbonate (2×10 ml) and brine (15 ml), then dried with sodium sulfate. The solvent was removed under reduced pressure to yield 237 mg product. The product eluted at 9.5 minutes by reverse phase (C18) HPLC at 0.11 trifluoroacetic acid in 5-75% aqueous acetonitrile over 20 minutes.
