Pyridine → HCID 11049983, compound

Participants

Reaction Steps

A solution of nucleoside 30 (5.35 g, 10 mmol) in anhyd dichloromethane (300 mL) was cooled to 0° C. Anhyd pyridine (8.08 mL, 100 mmol) and DMAP (4.89 g, 40 mmol) was added followed by the dropwise addition of trifluoromethansulfonic anhydride (3.3 mL, 20 mmol). After 2 h at 0° C. the reaction was quenched by the addition of ice cold sat. aq NaHCO3 (200 mL) and the reaction mixture was transferred to a separatory funnel. The phases were separated and the aq phase was extracted with dichloromethane (200 mL). The combined organic phases were washed with aq HCl (1.0 M, 2×300 mL) and sat. aq NaHCO3 (300 mL), dried (Na2SO4), filtered and concentrated in vacuo to give a white solid. The solid was dissolved in anhyd DMF (300 mL) and NaN3 (1.86 g, 30 mmol) was added. After stirring at rt for 4 h brine (300 mL) was added and the mixture was transferred to a separatory funnel. The aq phase was extracted with dichloromethane (3×200 mL) and the combined organic phases were dried (Na2SO4), filtered and concentrated in vacuo yielding a yellow residue that was purified by DCVC (Ø 5 cm, 25-100% EtOAc in n-heptane v/v, 5% increments, 100 mL fractions) affording nucleoside 32 (5.1 g, 91% from 30) as a white solid. Analytical data were identical to those reported above.

Provenance & Evidence