Thionyl Chloride → 2-Fluoropyridine-3-carbonyl chloride

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 2-fluoro-3-pyridinecarboxylic acid (6.3 g, 44.6 mmol) in DCM (112 mL) was added thionyl chloride (15.0 mL, 205 mmol). The reaction was heated to 40° C. and stirring continued for 3.5 h. After which, the reaction mixture was concentrated in vacuo to provide 2-fluoronicotinoyl chloride as a yellow solid. The product was taken on crude to the next step. To a stirred solution of 2-fluoronicotinoyl chloride (6.3 g, 39.5 mmol) in acetonitrile (197 mL, 39.5 mmol) was added diisopropylethylamine (27.5 mL, 158 mmol) followed by picolinimidamide (5.26 g, 43.4 mmol). The reaction was heated to 90° C. and stirring continued for 27 h. The reaction mixture was filtered and the filtrate was concentrated in vacuo. The residue was placed in Et2O (100 mL) and the mixture was filtered and was further washed with Et2O. The product was dried under vacuum and used crude in the next reaction. Mass Spectrum (ESI) m/e=225.1 (M+1).

Provenance & Evidence