反应 #356117

反应方程式

2-bromo-3-hydroxypyridine

Tf2O

→

title compound

收率 94.0%

Trifluoro-methanesulfonic acid 2-bromo-pyridin-3-yl ester

收率 94.0%

溶剂

pyridine

反应条件

后处理

1. 1
   其他at −10° C.
2. 2
   其他the temperature below −5° C. (30 min)
3. 3
   其他The cooling bath was removed
4. 4
   其他to reach 23° C.
5. 5
   workup.ADDITIONpoured into sat. NaHCO3-sol
6. 6
   萃取, extracted with DCM
7. 7
   洗涤washed with brine
8. 8
   干燥dried over Na2SO4
9. 9
   其他Removal of the solvent in vacuum
10. 10
    workup.WAITleft a brown oil, which
11. 11
    workup.DISTILLATIONwas purified by vacuum distillation
12. 12
    其他triturated with hexane
13. 13
    过滤filtered the undesired solid off,
14. 14
    洗涤washed with hexane
15. 15
    其他collected the mother liquor
16. 16
    其他evaporated the solvent

实验过程

To a solution of 2-bromo-3-hydroxypyridine [CAS 6602-32-0, commercially available] (25.0 g, 144 mmol) in anhydrous pyridine (145 mL) at −10° C. (ice/NaCl) was drop wise added Tf2O (24.2 mL, 147 mmol) keeping the temperature below −5° C. (30 min). The cooling bath was removed and mixture was allowed to reach 23° C., stirred at 23° C. for 75 min, poured into sat. NaHCO3-sol., extracted with DCM, washed with brine, dried over Na2SO4. Removal of the solvent in vacuum left a brown oil, which was purified by vacuum distillation: bp 65° C. (0.82 mbar) (42 g colorless oil, with some solid); triturated with hexane, filtered the undesired solid off, washed with hexane, collected the mother liquor, evaporated the solvent to give the title compound as a colorless liquid (41.52 g, 94%). MS (TOF ESP) 306 [(M+H)+], 307.85 [(M+2+H)+].

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