反応 #89031

反応方程式

5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione

[(2S,4R,5R)-4-azido-5-methoxy-tetrahydrofuran-2-yl]methyl benzoate

compound 33a

[(2S,4R,5R)-4-azido-5-methoxy-tetrahydrofuran-2-yl]methyl benzoate

TMSOTf

→

crude product

収率 29.3%

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

収率 29.3%

溶媒

ACN

反応条件

後処理

1. 1
   workup.ADDITIONwas added BSA (2.8 mg, 13.8 mmol)
2. 2
   その他The resulting reaction mixture
3. 3
   その他to form a clear solution
4. 4
   温度After the solution was cooled to room temperature
5. 5
   温度After being heated
6. 6
   workup.STIRRINGwith stirring at 70° C. for 14 hours
7. 7
   その他the solvent was removed in vacuo
8. 8
   その他The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL)
9. 9
   その他The organic layer was separated
10. 10
    抽出the aqueous phase was extracted with EtOAc (30 mL) twice
11. 11
    洗浄The combined organic layers were washed with brine
12. 12
    乾燥dried over Na2SO4
13. 13
    濃縮concentrated in vacuo

実験手順

To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (730 mg, 3.97 mmol) in ACN (15 mL) was added BSA (2.8 mg, 13.8 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,5R)-4-azido-5-methoxy-tetrahydrofuran-2-yl]methyl benzoate (compound 33a, crude, 1.1 g, 3.97 mmol) and TMSOTf (4.4 g, 19.5 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 500 mg crude product of [(2S,4R,5R)-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)-4-azido-tetrahydrofuran-2-yl]methyl benzoate (compound 33b) as a yellow solid. MS obsd. (ESI+) [(M+H)+]: 430.

出典