Pyridine, hydrofluoride (1:1) → Methyl 5-fluoro-3-pyridinecarboxylate
Reaction equation
N[C:2]1[CH:3]=[N:4][CH:5]=[C:6]([CH:11]=1)[C:7]([O:9][CH3:10])=[O:8].N([O-])=O.[Na+].C1C=CN=CC=1.[FH:22]>>[F:22][C:2]1[CH:3]=[N:4][CH:5]=[C:6]([CH:11]=1)[C:7]([O:9][CH3:10])=[O:8]Participants
4
Conditions
- Temperature
- 50 °C
Procedure
To a stirring solution of 243 mg (1.6 mmol) of methyl 5-aminonicotinate in 5 mL of HF-pyridine at 0° C. was added 119 mg (1.72 mmol) of NaNO2. The mixture was stirred at 0° C. for 30 min. and at 50° C. for 1 h. The reaction was quenched by ice and sat. NaHCO3 solution. The aqueous layer was extracted with CHCl3, dried over Na2SO4, filtered, and concentrated. Purification by flash silica gel chromatography (1% MeOH/CHCl3) provided 139 mg of methyl 5-fluoronicotinate as a yellow solid in 56% yield.
Workup
- customThe reaction was quenched by ice and sat. NaHCO3 solution
- extractionThe aqueous layer was extracted with CHCl3
- dry with materialdried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customPurification by flash silica gel chromatography (1% MeOH/CHCl3)
Sources & evidence
- ORD record
- ord-ab18c6ac634844d4a609487fa0e5d6d4
- Source dataset
- uspto-grants-2009_03
- Patent number
- US07504420B2
Reaction notes
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