Trifluoroacetic acid → N-[4-[(3S,5R)-3-amino-5-methylpiperidin-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,5R)-3-[(tert-Butoxycarbonyl)amino]-5-methylpiperidin-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, 0.0043 mmol) was dissolved in MeOH (0.02 mL) and THF (0.08 mL), followed by the addition of 1.0 M aq. NaOH (0.017 mL, 0.017 mmol). The reaction mixture was stirred at room temperature for 20 min. The organic solvents and trace of water were removed under vacuum to give the crude intermediate, which was dissolved in DCM (0.044 mL), followed by the addition of TFA (0.044 mL, 0.56 mmol). The reaction mixture was stirred at room temperature for 20 min. After concentration, 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