反应 #89009

反应方程式

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

1-[(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl benzoate

compound 26b

1-[(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl benzoate

TMSOTf

→

crude product

收率 79.3%

1-[(2S,4R,5R)-4-acetoxy-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)tetrahydrofuran-2-yl]propyl benzoate

收率 79.3%

溶剂

ACN

反应条件

后处理

1. 1
   workup.ADDITIONwas added BSA (10.4 mL, 42 mmol)
2. 2
   其他The resulting reaction mixture
3. 3
   其他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
   其他the solvent was removed in vacuo
8. 8
   其他The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL)
9. 9
   其他The organic layer was separated
10. 10
    萃取the aqueous phase was extracted with EtOAc (30 mL) twice
11. 11
    洗涤The combined organic layers were washed with brine
12. 12
    干燥dried over Na2SO4
13. 13
    浓缩concentrated in vacuo
14. 14
    其他The residue was purified by column chromatography on silica gel (eluting with 1:200 methanol in DCM)

实验过程

To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (2.82 g, 16.8 mmol) in ACN (100 mL) was added BSA (10.4 mL, 42 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, 1-[(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]propyl benzoate (compound 26b, 4.9 g, 14.0 mmol) and TMSOTf (4.7 mL, 2.3 21 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. The residue was purified by column chromatography on silica gel (eluting with 1:200 methanol in DCM) to afford 5.27 g crude product of 1-[(2S,4R,5R)-4-acetoxy-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)tetrahydrofuran-2-yl]propyl benzoate (compound 26c) as a light yellow solid. MS obsd. (ESI+) [(M+H)+]: 475.

来源