Trifluoroacetic acid → N-[4-[(3S)-3-aminopiperidin-1-yl]-7-hydroxy-6,7-dihydro-5H-cyclopenta[b]pyridin-3-yl]-6-(2,6-difluoro-4-methylsulfinylphenyl)-5-fluoropyridine-2-carboxamide

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Reaction Steps

4-{(3S)-3-[(tert-Butoxycarbonyl)amino]piperidin-1-yl}-3-[({6-[2,6-difluoro-4-(methylsulfinyl)phenyl]-5-fluoropyridin-2-yl}carbonyl)amino]-6,7-dihydro-5H-cyclopenta[b]pyridin-7-yl acetate (3.0 mg, 0.0044 mmol) was dissolved in MeOH (0.01 mL) and THF (0.05 mL), and 1.0 M aq. NaOH (0.017 mL, 0.017 mmol) was then added. The reaction mixture was stirred at room temperature for 60 min. The organic solvents and trace of water were removed under reduced pressure to give a crude intermediate. The residue was dissolved in DCM (0.04 mL), then TFA (0.044 mL, 0.58 mmol) was added. The reaction mixture was stirred at room temperature for 16 h. The solution was then concentrated again under reduced pressure. The residue was diluted with MeOH, filtered and purified by preparative LC-MS (XBridge™ preparative C18 5 μm OBD™ column, 30×10 mm, 60 mL/min., eluting with a gradient of MeCN and water with 0.1% NH4OH) to give two mixtures of diastereoisomers of the title compound as white powders. On analytical HPLC (Waters SunFire™ C18, 2.1×50 mm, 5 μm; flow rate 3 mL/min.; injection volume 2 μL; gradient from 2 to 80% B in 3 minutes (A=water with 0.025% TFA, B=MeCN)) the diastereoisomers had the following properties:

Provenance & Evidence