Trimethylsilyl triflate → 5-amino-3-[(2R,3R,5S)-5-[[tert-butyl(diphenyl)silyl]oxymethyl]-3-(1-fluoro-1-methyl-ethyl)tetrahydrofuran-2-yl]-6H-thiazolo[4,5-d]pyrimidine-2,7-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (162 mg, 0.87 mmol) and bis(trimethylsilyl)acetamide (527 mg, 2.61 mmol) was heated with stirring at 75° C. under argon until the mixture became clear. The mixture was cooled to room temperature. To the previous reaction mixture, [(3R,5S)-5-[[tert-butyl(diphenyl)silyl]oxymethyl]-3-(1-fluoro-1-methyl-ethyl)tetrahydrofuran-2-yl]acetate (compound 40g, 280 mg, 1.02 mmol) and trimethylsilyltrifluoromethanesulfonate (290 mg, 1.31 mmol) were introduced. The resulting mixture was heated at 75° C. under argon for 3 hours. Then the resulting mixture was concentrated in vacuo to remove the solvent and the residue was purified by column chromatography on silica gel (eluting with 0-5% methanol in DCM) to afford 225 mg of 5-amino-3-[(2R,3R,5S)-5-[[tert-butyl(diphenyl)silyl]oxymethyl]-3-(1-fluoro-1-methyl-ethyl)tetrahydrofuran-2-yl]-6H-thiazolo[4,5-d]pyrimidine-2,7-dione (compound 40h) as a brown solid. MS obsd. (ESI+) [(M+H)+]: 583.

Provenance & Evidence