Bicarbonate Ion → TFA-ap-dC

Participants

Reaction Steps

To a solution of 5-iodo-2′-deoxycytidine (10 g, 28.32 mmol) in DMF (200 ml) in a light protected round bottom flask under Argon atmosphere, was added CuI (1.08 g, 5.67 mmol), triethylamine (7.80 ml, 55.60 mmol), 2,2,2-trifluoro-N-prop-2-ynyl-acetamide (12.8 g, 84.76 mmol) and at last Pd(PPh)3)4 (3.27 g, 2.83 mmol). After 18 hours at room temperature, dowex bicarbonate (20 mg) was added and the mixture was stirred for a further 1 h. Filtration and evaporation of the volatiles under reduced pressure gave a residue that was purified by flash chromatography on silica gel (CH2Cl2, CH2Cl2:EtOAc 1:1, EtOAc:MeOH 9:1). The expected product (7) was obtained as a beige solid in quantitative yield. 1H NMR (D2O) δ 2.24-2.17 (m, 1H, H-2′), 2.41-2.37 (m, 1H, H-2′), 3.68 (dd, J=12.5, 5.0 Hz, 1H, H-5′), 3.77 (dd, J=12.5, 3.2 Hz, 1H, H-5′), 3.99 (m, 1H, H-4′), 4.27 (s, 2H, CH2N), 4.34 (m, 1H, H-3′), 6.11 (t, J=6.3 Hz, 1H, H-1′), 8.1 (br s, 1H, NH); MS (ES): m/z (%) (M−H) 375 (100).

Provenance & Evidence