2-Bromo-3-pyridinol → 2-Bromo-3-pyridyl trifluoromethanesulfonate

Participants

Reaction Conditions

Reaction Steps

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)+].

Provenance & Evidence