Trimethylsilyl triflate → [(2S,4R,5R)-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)-4-pyrrolidin-1-yl-tetrahydrofuran-2-yl]methyl benzoate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (138 mg, 0.75 mmol) in ACN (5 mL) was added BSA (535 mg, 2.6 mmol). The resulting reaction mixture was then stirred at 70° C. under argon for 0.5 hour to form a clear solution. After the solution was cooled to room temperature, [(2S,4R)-5-methoxy-4-pyrrolidin-1-yl-tetrahydrofuran-2-yl]methyl benzoate (compound 32d, 230 mg, 0.75 mmol) and TMSOTf (832 mg, 3.75 mmol) were added in sequence. After being heated with stirring at 70° C. for 14 hours, the solvent was removed in vacuo. The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL). The organic layer was separated and the aqueous phase was extracted with EtOAc (30 mL) twice. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo to afford 250 mg crude product of [(2S,4R,5R)-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)-4-pyrrolidin-1-yl-tetrahydrofuran-2-yl]methyl benzoate (compound 32e) as a yellow solid. MS obsd. (ESI+) [(M+H)+]: 458.

Provenance & Evidence