Benzyl [2-{[(4-{(3S)-3-[(tert-butoxycarbonyl)amino]piperidin-1-yl}pyridin-3-yl)amino]carbonyl}-7-(1-hydroxyethyl)quinolin-3-yl]carbamate (8.0 mg, 0.012 mmol) (from Example 15, step 6) was dissolved in DCM (0.3 mL), cooled to −78° C., and then treated with diethylaminosulfur trifluoride (50 mg, 0.3 mmol). The resulting reaction mixture allowed to warm to room temperature and stirred at room temperature for 2 h. The reaction mixture was poured into ice-water containing NaHCO3, extracted three times with DCM, dried over Na2SO4, filtered and concentrated under reduced pressure. HBr in AcOH (8.0 M; 0.20 mL, 1.6 mmol) was added to the residue. The reaction mixture was stirred at room temperature for 30 min., and then concentrated under reduced pressure. The residue was diluted with MeOH and neutralized with small amounts of NH4OH. The mixture was filtered and purified by preparative LC-MS (pH=10 method; XBridge™ preparative C18 5 μm OBD™ column, 30×10 mm, 60 mL/min., eluting with a gradient of MeCN and water with NH4OH) to give the title compound. LCMS calc. for C22H26FN6O (M+H)+: m/z=409.1. Found: 409.0.
