Water → 6-Fluoropyridine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a heterogeneous solution of 2-fluoro-6-methyl-pyridine (9.65 g, 86.8 mmol) in water (400 mL) was added potassium permanganate (31.6 g, 200 mmol), and the reaction was heated to approximately 100° C. After 30 minutes, additional potassium permanganate (16.5 g, 104 mmol) was added, and the reaction heated at 100° C. overnight. The reaction was filtered through celite to remove manganese salts. The mother liquor was washed with ethyl ether (200 mL×3), neutralized to pH 7, and concentrated down to approximately 100 mL total volume. The aqueous solution was acidified to pH 2 with concentrated HCl and extracted with ethyl acetate, followed by 20% i-PrOH/CHCl3 (×3). The combined organic layers were dried over MgSO4 and concentrated. The solids were suspended in chloroform, sonicated, then filtered to remove remaining side products. The mother liquor was concentrated to give 5.47 g as a white crystalline solid, 45% yield. 1H NMR: consistent with structure. MS (ion spray) 140 (M−).

Provenance & Evidence