Hydrochloric Acid → N-[(6-Amino-2-methyl(3-pyridyl))methyl]-2-[3-[(2,2-difluoro-2-phenylethyl)amino]-6-chloro-2-fluorophenyl}acetamide Hydrochloride Salt

To a flask charged with 2-{3-[(2,2-difluoro-2-phenylethyl)amino]-6-chloro-2-fluorophenyl}-N-({6-[(tert-butoxy)carbonylamino]-2-methyl(3-pyridyl)}methyl)acetamide (770 mg, 1.37 mmol), as prepared in the preceding step, was added a solution of HCl in 1,4-dioxane (5 mL, 20 mmol, 4.0 M). After stirring at ambient temperature for 1.5 hours, some solid precipitated. A solution of MeOH (1 mL) in DCM (3 mL) was added to dissolve the solid, and the mixture was stirred for additional 4 hours. The solvents were removed, and the resulting residue was washed with DCM (5 mL×2), ether (8 mL×2), and dried in high vacuum to give the title compound (620 mg, 91% yield) as a pale brown solid. 1H-NMR (400 MHz, CD3OD) δ 7.81 (d, J=9.1 Hz, 1H), 7.54-7.51 (m, 2H), 7.45-7.42 (m, 3H), 6.94 (dd, J=8.9, 1.6 Hz, 1H), 6.80 (d, J=9.1 Hz, 1H), 6.65 (t, J=9.1 Hz, 1H), 4.25 (s, 2H), 3.81 (t, J=13.8 Hz, 2H), 3.70 (d, J=1.8 Hz, 2H), 2.50 (s, 3H). Mass spectrum (LCMS, ESI) calcd for C23H23ClF3N4O (M+H): 463.1. Found: 463.7.