Benzoic Acid → Benzoyl fluoride

Participants

Reaction Steps

To a suspension of diethylaminosulfinium tetrafluoroborate (344 mg, 1.5 mmol) in dichloromethane (3.0 mL) at room temperature is added benzoic acid (122 mg, 1.0 mmol) and DBU (224 μl, 1.5 mmol). The reaction mixture is stirred for 4 hours, then an 10% aqueous solution of HCl is added and stirring is continued for 15 minutes. The resulting mixture is extracted twice using dichloromethane. The organic phases are combined, dried over magnesium sulphate, filtered and concentrated. The crude material is diluted with pentane and the solution is passed through a pad of silica gel with pentane elution. Solvent are evaporated in vacuum to provide benzoyl fluoride (90 mg, 74%) as a clear liquid. 1H NMR (CDCl3, 300 MHz) δ 7.94 (d, J=7.8, 2H), 7.62 (t, J=7.3 Hz, 1H), 7.43 (t, J=8.2 Hz, 2H); 19F NMR (CDCl3, 282 MHz) δ 17.5 (s, 1F); 13C NMR (CDCl3, 75 MHz) δ 157.3 (d, 1JC-F=344.3 Hz), 135.5, 131.5 (d, 3JC-F=4.0 Hz), 129.2, 125.0 (d, 2JC-F=60.4 Hz).

Provenance & Evidence