115899-40-6

14719-21-2

54-42-2

115899-40-6

To a solution of 5-iodouridine (5.0 g, 14.1 mmol) in anhydrous DMF (40 mL), CuI (0.20 g, 1.05 mmol) and Pd(PPh3)4 (0.41 g, 0.35 mmol) were added under nitrogen protection. After stirring for 10 min, triethylamine (4.0 mL, 28.6 mmol) and 2,2,2-trifluoro-N-(prop-2-yn-1-yl)acetamide (5.4 g, 35.7 mmol) were added sequentially and the reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, all volatiles were removed under vacuum and the residue was purified by rapid chromatography on silica gel [eluent: EtOAc/MeOH (0-15%)] to afford the target product 2,2,2-trifluoro-N-(3-(1-((2R,4S,5R)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)-2,4-dioxo-1,2,3,4- (tetrahydropyrimidin-5-yl)prop-2-ynyl)acetamide as a yellow solid (4.1 g, 76% yield).1H-NMR (DMSO-d6) δ: 11.68 (br s, 1H, NH), 10.02 (s, 1H, NH), 7.94 (s, 1H, H-6), 6.11 (t, J = 7.2 Hz, H-1'), 5.29 (d, J = 0.4 Hz, NH), 6.11 (t, J = 0.4 Hz, NH), 5.29 (d, J = 0.4 Hz, NH). J = 0.4 Hz, 1H, OH), 4.21 (m, 3H, H-3', NCH2), 3.71-3.83 (m, 2H, CH2-5'), 2.15-2.19 (m, 1H, H-2'), 2.03-2.08 (m, 1H, H-2'). Mass Spectra (ESI): Calculated value C14H14F3N3O6 (M + Na)+ 400, measured value 400.