A solution of (5-(4-(bis (4-methoxybenzyl)amino)-6-methyl-1,3,5-triazin-2-yl)-6-(6-methoxypyridin-3-ylamino)pyridin-3-yl)methanol (100.7 mg, 0.174 mmol) and trifluoromethanesulfonic acid (0.07 mL, 0.788 mmol) in 2,2,2-trifluoroacetic acid (3.5 mL) was stirred at 75° C. for 1 h. The mixture was subsequently cooled to 25° C. and concentrated in vacuo. NaOH (1.0 N, aq.; 2.0 mL) was added, followed by MeOH (1.0 mL) (final pH>10), and the resulting mixture was stirred at 25° C. for 5 min. MeOH was removed in vacuo, and the resulting mixture was vacuum filtered. The collected solid was sequentially washed with water (20 mL) and ethyl ether (6 mL) and then dried in vacuo. Chromatographic purification of this solid (ISCO, 4 g, 0 to 10% MeOH/DCM) furnished (5-(4-amino-6-methyl-1,3,5-triazin-2-yl)-6-(6-methoxypyridin-3-ylamino)pyridin-3-yl)methanol (41.8 mg, 0.123 mmol, 70.9% yield) as a yellow solid. 1H NMR (400 MHz, d4-MeOH) δ 8.94 (d, J=2.54 Hz, 1H); 8.48 (d, J=2.35 Hz, 1H), 8.25 (d, J=2.54 Hz, 1H); 8.07 (dd, J=8.80, 2.74 Hz, 1H); 6.85 (d, J=9.00 Hz, 1H); 4.60 (s, 2H); 3.94 (s, 3H); 3.38 (s, 2H); 2.52 (s, 3H). m/z (ESI, +ve ion) 340.1 (M+H)+.
