HCID 70103771, compound → HCID 70105569, compound

Participants

Reaction Steps

Hydrogen bromide gas was bubbled into an ice-cooled solution of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (2.02 g) in dichloromethane (15 ml) for 15 min. The reaction was stirred at 0° for 1 hour then at room temperature for 15 min. The solution was concentrated and the residue azeotroped with dichloromethane (3×50 ml). Sodium hydride (60%, 0.19 g) was added to a stirred suspension of the product of step b) (1.08 g) in acetonitrile (29 ml). After stirring at room temperature for 15 min the bromo sugar described above, in acetonitrile (10 ml), was added and stirring continued for 24 hours. The reaction mixture was partitioned between ethyl acetate and water, the organic layer was dried and concentrated. Chromatography (SiO2, dichloromethane:diethylether, 39:1, as eluant) gave a mixture of 5,7-bis(propylthio)-3-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-3H-1,2,3-triazolo[4,5-d]pyrimidine [MS (FAB): 714 (M+H+), 105 (100%)] and 5,7-bis(propylthio)-2-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-2H-1,2,3-triazolo[4,5-d]pyrimidine [MS (FAB): 714 (M+H+), 105 (100%)] (1.9 g). Further elution gave 5,7-bis(propylthio)-1-(2,3,5-tri-O-benzoyl-β-D-ribo-furanosyl)-1H-1,2,3-triazolo[4,5-d]pyrimidine as a colourless foam (0.46 g).

Provenance & Evidence