반응 #356117

반응 방정식

2-bromo-3-hydroxypyridine

Tf2O

→

title compound

수율 94.0%

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

수율 94.0%

용매

pyridine

반응 조건

후처리

1. 1
   기타at −10° C.
2. 2
   기타the temperature below −5° C. (30 min)
3. 3
   기타The cooling bath was removed
4. 4
   기타to reach 23° C.
5. 5
   workup.ADDITIONpoured into sat. NaHCO3-sol
6. 6
   추출, extracted with DCM
7. 7
   세척washed with brine
8. 8
   건조dried over Na2SO4
9. 9
   기타Removal of the solvent in vacuum
10. 10
    workup.WAITleft a brown oil, which
11. 11
    workup.DISTILLATIONwas purified by vacuum distillation
12. 12
    기타triturated with hexane
13. 13
    여과filtered the undesired solid off,
14. 14
    세척washed with hexane
15. 15
    기타collected the mother liquor
16. 16
    기타evaporated the solvent

실험 절차

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)+].

출처