Hydrogen Bromide → 4-Chloro-7-[3,5-bis-o-(2,4-dichlorophenylmethyl)-2-c-vinyl-beta-d-ribofuranosyl]-7h-pyrrolo[2,3-d]pyrimidine

Participants

Reaction Steps

To a solution of the compound from Step A (6.4 g, 12.6 mmol) in anhydrous dichloromethane (150 mL) at −20° C. was added HBr (30% solution in AcOH, 20 mL, 75.6 mmol) dropwise. The resulting solution was stirred between −10° C. and 0° C. for 4 h, evaporated in vacuo and co-evaporated with anhydrous toluene (3×40 mL). The oily residue was dissolved in anhydrous acetonitrile (100 mL) and added to a solution of the sodium salt of 4-chloro-1H-pyrrolo[2,3-d]pyrimidine (5.8 g, 37.8 mmol) in acetonitrile (generated in situ as described in Example 2) at −20° C. The resulting mixture was allowed to come to room temperature and stirred at room temperature for 24 h. The mixture was then evaporated to dryness, taken up in water and extracted with EtOAc (2×300 mL). The combined extracts were dried over Na2SO4, filtered and evaporated. The crude mixture was purified by flash chromatography (SiO2, 10% EtOAc in hexanes) and the title compound (1.75 g) isolated as a white foam.

Provenance & Evidence