Water → 2-Fluoroisonicotinic acid

Participants

Reaction Steps

A stirred mixture of 30 grams of the above 2-fluoro-4-methylpyridine and potassium permanganate (100 g) in water (1.2 L) was heated at reflux. Additional potassium permanganate (50 g) was added after 1.5 hours and the stirred mixture was maintained at reflux for 15 hours. The reaction mixture was then steam distilled to remove unreacted starting material, the hot residual aqueous solution was filtered, and the filtrate was concentrated in vacuo to 450 mL. The solution was cooled on an ice-bath and acidified with concentrated HCl to pH 2.0. The resulting precipitate was collected and crystallized from water and gave 13.56 g of 2-fluoropyridine-4-carboxylic acid having a melting point of 220°-224° C.

Provenance & Evidence