Pyridine → HCID 22881709, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred, cold solution of 3′-O-(4,4′-dimethoxytrityl)thymidine (prepared from thymidine by the common procedures, 40.4 g, 0.072 mol) in anhydrous DMSO was added a solution of DCC (45.86 g, 0.224 mol) in DMSO (180 ml). The resulting solution was stirred at 5° C. for 5 min. pyridine (2.94 g, 3.0 ml, 0.0371 mol) was added and after stirring for another 5 min. a solution of trifluorocaetic acid (2.11 g, 1.43 ml, 0.0185 mol) in DMSO (2 ml) was added dropwise. The resulting reaction mixture was stirred at 5° C. for 10 min. and at room temperature for 6 h. Water (20 ml) was added dropwise under cooling and the mixture stirred at room temperature for 1 h. Precipitates were filtered and washed with DMSO. The combined DMSO solution was poured onto crashed ice (4 L) with stirring. After standing for 1 h, the precipitates were filtered and washed thoroughly with water. The cake was dissolved in methylene chloride (500 ml), and the organic layer separated, dried (Na2SO4), and concentrated. The crude was purified by chromatography on silica (3% methanol in methylene chloride) to give 32.6 g (81%) of 3′-O-(4,4′dimethoxytrityl)-5′-formylthymidine as a colorless powder.

Provenance & Evidence