Trifluoromethanesulfonic anhydride → Methyl 3-(trifluoromethylsulfonyloxy)-pyridine-2-carboxylate
Reaction equation
[S:1]([O:8]S(C(F)(F)F)(=O)=O)([C:4]([F:7])([F:6])[F:5])(=[O:3])=[O:2].O[C:17]1[C:18]([C:23]([O:25][CH3:26])=[O:24])=[N:19][CH:20]=[CH:21][CH:22]=1>C(Cl)Cl>[F:5][C:4]([F:7])([F:6])[S:1]([O:8][C:17]1[C:18]([C:23]([O:25][CH3:26])=[O:24])=[N:19][CH:20]=[CH:21][CH:22]=1)(=[O:3])=[O:2]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
Triflic anhydride (5.0 g, 18.0 mmol) was added dropwise to a cold (0° C.) solution of methyl 3-hydroxypicolinate (2.5 g, 16.3 mmol) and TEA (2.5 mL, 18.0 mmol) in CH2Cl2 (80 mL). The mixture was stirred at 0° C. for 1 h before it was allowed to warm up to room temperature where it stirred for an additional 1 h. The mixture was then quenched with saturated NaHCO3 solution (40 mL) and the organic layer was separated, washed with brine, dried over MgSO4 and concentrated to give methyl 3-(trifluoromethylsulfonyloxy)picolinate (i.e., Cap-174, Step a) (3.38 g, 73%) as a dark brown oil (>95% pure) which was used directly without further purification. 1H NMR (300 MHz, CDCl3) δ ppm 8.72-8.79 (1H, m), 7.71 (1H, d, J=1.5 Hz), 7.58-7.65 (1H, m), 4.04 (3H, s). Rt=1.93 min (Cond.-MD1); LC-MS: Anal. Calcd. for [M+H]+ C8H7F3NO5S: 286.00. found: 286.08.
Workup
- temperatureto warm up to room temperature where it
- stirringstirred for an additional 1 h
- customThe mixture was then quenched with saturated NaHCO3 solution (40 mL)
- customthe organic layer was separated
- washwashed with brine
- dry with materialdried over MgSO4
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-90118ad3ce294ac9bec92a2ceeff67d3
- Source dataset
- uspto-grants-2013_02
- Patent number
- US08377980B2
Reaction notes
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