反应 #74492

反应方程式

Et2O

3-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-4,5-dihydro-1,2,4-triazin-6(1H)-one

compound 55

3-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-4,5-dihydro-1,2,4-triazin-6(1H)-one

CH2Cl2

DDQ

→

title compound

收率 35.0%

6-Chloro-3-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-1,2,4-triazine

收率 35.0%

溶剂

water

water

water

反应条件

后处理

1. 1
   干燥Normal work-up with CH2Cl2 and drying with MgSO4
2. 2
   其他Without further purification, it
3. 3
   其他was reacted with POCl3 (2 ml) in toluene (20 ml)
4. 4
   温度under refluxed condition
5. 5
   其他After reaction complete
6. 6
   其他After work-up with CH2Cl2, organic layer was evaporated under reduced pressure
7. 7
   其他The residue was purified with use of column chromatography (Hexane/EtOAc=½)

实验过程

The 3-(2-chloro-5-((2S,3S,4R,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)tetrahydro-2H-pyran-2-yl)benzyl)-4,5-dihydro-1,2,4-triazin-6(1H)-one (compound 55, 826 mg, 1.11 mmol) in a mixture of CH2Cl2 (20 ml) and water (2 ml) treated with DDQ (504 mg, 2.22 mmol) at 0° C. After 3 hours, Et2O and water were added to the reaction mixture. Normal work-up with CH2Cl2 and drying with MgSO4 generated crude title compound. Without further purification, it was reacted with POCl3 (2 ml) in toluene (20 ml) under refluxed condition. After reaction complete, the resulting solution was poured into iced water (50 ml). After work-up with CH2Cl2, organic layer was evaporated under reduced pressure. The residue was purified with use of column chromatography (Hexane/EtOAc=½) to provide title compound (296 mg, 35% overall yield) as yellow oil.

来源