Cesium fluoride → 6-(4-Fluorophenyl)pyridine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Combine 6-bromopyridine-3-carboxylic acid methyl ester (1.03 g, 4.78 mmol), 4-fluorophenylboronic acid (1.88 g, 13.41 mmol), and cesium fluoride (2.55 g, 16.78 mmol) in DMF (25 mL) and water (4 mL) with stirring. Place the hetereogeneous reaction mixture, open to the air, in an oil bath maintained at 80° C. After 5 minutes of heating, add Pd(OAc)2 (150 mg, 0.67 mmol) in one portion. After 17 hours, cool the reaction to room temperature, dilute with ethyl acetate and filter through a short plug of celite with additional ethyl acetate. Wash the organics with water, dry over MgSO4, filter and evaporate. Purification by flash column chromatography yields 6-(4-fluorophenyl)pyridine-3-carboxylic acid methyl ester as a yellow solid. Dissolve the purified ester in THF (0.25 M) and add an equal volume of 1 M NaOH. Stir vigorously at room temperature for 15 hours. Upon completion, acidify the reaction with conc. HCl and collect the white precipitate by filtration. Drying under vacuum yields 385 mg (37%) of the title compound. MS (ES): m/z 218.1 (M+H).

Provenance & Evidence