Trimethylsilyl triflate → (2R,3R,4S,5S)-4-(Benzoyloxy)-2-(2-cyano-6-[(1-naphthylmethyl)amino]-9H-purin-9-yl}-5-[(ethylamino)carbonyl]tetrahydro-3-furanyl benzoate

Participants

Reaction Steps

Diazabicycloundecane (0.18 ml, 1.2 mmol) was added to a solution of (6-[(1-naphthylmethyl)amino]-9H-purine-2-carbonitrile (200 mg, 0.67 mmol) (Preparation 10) and (2S,3S,4R,5R)-5-(acetyloxy)-4-(benzoyloxy)-2-[(ethylamino)carbonyl]tetrahydro-3furanyl benzoate and (2S,3S,4S,5S)-5-(acetyloxy)-4-(benzoyloxy)-2-[(ethylamino)carbonyl]tetrahydro-3-furanyl benzoate (309 mg, 0.70 mmol) (Preparation 18) in acetonitrile (5 ml). Trimethylsilyl trifluoromethanesulfonate (0.24 ml, 1.33 mmol) was added and the reaction mixture heated under reflux for 30 minutes. The reaction mixture was then allowed to cool to room temperature, diluted with ethyl acetate (20 ml) and washed twice with water (20 ml). The ethyl acetate layer was then washed with 10% w/w aqueous citric acid and saturated aqueous sodium chloride solution (20 ml). The organic phase was dried over anhydrous magnesium sulphate and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with dichloromethane increasing in polarity to dichloromethane:methanol (98:2 by volume). The solvent was removed under reduced pressure to give the title compound (235 mg) as a foam.

Provenance & Evidence