3-({[3-Amino-6-(2,6-difluorophenyl)-5-fluoropyridin-2-yl]carbonyl}amino)-4-{(3S)-3-[(tert-butoxycarbonyl)amino]piperidin-1-yl}-6,7-dihydro-5H-cyclopenta[b]pyridin-7-yl acetate (4.0 mg, 0.0062 mmol) was mixed with MeOH (74 μL), THF (37 μL) and 1.0 M NaOH (41 μL, 0.041 mmol). The reaction mixture was stirred at room temperature for 30 min. The organic solvents were removed under reduced pressure. The aqueous layer was diluted with aq. NH4Cl, then extracted twice with EtOAc. The combined organic layers were dried, filtered and concentrated under reduced pressure to give an intermediate, which was treated with DCM (0.064 mL) and TFA (0.064 mL, 0.82 mmol). The resulting mixture was stirred at room temperature for 30 min., then concentrated under reduced pressure. The residue was diluted with MeOH and neutralized with NH4OH. The resulting mixture was filtered and purified by preparative LC-MS (XBridge™ preparative C18 5 μm 30×10 mm OBD™ column, flow rate 60 mL/min., eluting with a gradient of MeCN and water with 0.15% NH4OH) to give two diastereoisomers of the title compound as white powders.
