342602-55-5

402-66-4

75-16-1

342602-55-5

Step A: 5-Fluoronicotinic acid (1.0 g, 7.1 mmol) was dissolved in anhydrous THF (10 mL) and cooled to 0°C under ice bath conditions. A THF/toluene (3:1, v/v) solution of 1.4 M methylmagnesium bromide (11.2 mL, 15.6 mmol) was slowly added dropwise under nitrogen protection. After the dropwise addition, the reaction mixture was gradually warmed up to room temperature and stirred continuously at that temperature for 4 hours. Subsequently, 1 N HCl aqueous solution (50 mL) was slowly added to quench the reaction. The reaction mixture was transferred to a partition funnel and extracted by partitioning with EtOAc (200 mL) and 1 N NaOH aqueous solution (200 mL). The organic layer was separated and washed with saturated brine and subsequently dried over anhydrous Na2SO4. The desiccant was removed by filtration and the filtrate was concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography using gradient elution with hexane/EtOAc (0% to 50%, v/v) to afford the target compound 1-(5-fluoropyridin-3-yl)ethanone as a white powder (290 mg, 29% yield).