2-{[4-(4-Bromophenyl)-1,3-thiazol-2-yl]amino}-3,3,3-trifluoropropan-1-ol (0.61 g, 1.6 mmol), prepared in the previous step, was dissolved in 48 mL methylene chloride. Triethylamine (2.2 mL, 16 mmol) was added and the solution was cooled to 0° C. Triphosgene (1.20 g, 4.15 mmol) was added in two portions and the mixture was stirred at 0° C. for 45 min and then at 25° C. for 2 h. The mixture was poured into 250 mL of saturated aqueous sodium bicarbonate and the layers were separated. The organics were washed with water, brine, dried over anhydrous MgSO4, filtered and concentrated under reduced pressure. Flash chromatography (gradient 2% acetone/hexane to 10% acetone/hexane) afforded the title compound (0.47 g, 75%) as a white solid, mp 154-156° C. HRMS: calcd for C13H8BrF3N2O2S+H, 392.95202; found (ESI, [M+H]+), 392.9518. Analytical HPLC: retention time 10.6 min, 210-370 nm the Xterra® RP18 column, 3.5μ, 150×4.6 mm 40° C. 85/15-5/95 (Ammon. Form. Buff. pH=3.5/ACN+MeOH) for 10 min, hold 4 min 1.2 mL/min 5 μL injection.
