A 20 mL vial was charged with 5-bromo-3-phenoxy-N-(4-(piperidin-4-yl)thiazol-2-yl)pyridin-2-amine dihydrochloride (80 mg, 0.159 mmol), triethylamine (0.088 mL, 0.64 mmol) and THF (2 mL). Acetic anhydride (0.015 mL, 0.16 mmol) was added and stirred at ambient temperature for 30 minutes. The reaction was poured into saturated aqueous NaHCO3 and extract with EtOAc (2×20 mL). The organic layer was dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified on silica gel (5% methanol in EtOAc) to afford the title compound (47.6 mg, 58.8% yield) as a white solid after HCl salt formation. 1H NMR (d6-DMSO) δ 11.00 (bs, 1H), 8.23 (d, 1H), 7.44 (m, 2H), 7.40 (d, 1H), 7.21 (t, 1H), 7.11 (d, 2H), 6.70 (s, 1H), 4.41 (d, 1H), 3.12 (m, 1H), 2.83 (tt, 1H), 2.62 (td, 1H), 2.50 (m, 1H), 2.00 (s, 3H), 1.93 (m, 2H), 1.55 (qd, 1H), 1.42 (qd, 1H). Mass spectrum (apci) m/z=475.2 (M+H—HCl).
