Oxalyl chloride → 2-Fluoropyridine-3-carbonyl chloride

A homogeneous mixture of 2-fluoronicotinic acid (Aldrich, 0.45 g, 3.2 mmol), in anhydrous THF (12 mL), was treated with oxalyl chloride (0.56 mL, 6.4 mmol) followed by anhydrous DMF (2 drops). After heating at reflux for 1.5 hours, the reaction mixture was concentrated in vacuo to afford 2-fluoronicotinoyl chloride as a residue which was used without further purification. The residue was dissolved in anhydrous THF (8 mL), anhydrous DCM (2 mL), pyridine (1 mL) and DMF (to a total volume of 16 mL). This homogeneous 2-fluoronicotinoyl chloride mixture (2 mL) was then added to a rapidly stirred mixture of o-toluidine (Aldrich, 0.17 mL, 1.6 mmol) in anhydrous THF (2 mL). After 15 hours, the reaction was quenched with water, and then extracted with 10% isopropanol in chloroform. The organic layer was washed once with sat. aq. NaHCO3, once with sat. aq. NaCl, then dried over anhydrous Na2SO4 and concentrated in vacuo to afford the desired product (0.084 g, 91%) as a pale orange solid which was used without further purification. MS(ESI+) m/z 231 (M+H)+.