Hydrochloric Acid → 5-Fluoro-2,3-dihydro-1-benzofuran-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a 500 ml round-bottomed flask that contained a solution of (5-fluoro-2,3-dihydro-benzofuran-2-yl)-methanol (3.0 g, 17.8 mmol) in 100 ml of acetonitrile was added a solution of potassium bicarbonate (7.14 g, 71.4 mmol, 4 eq) in 30 ml of water. The mixture was cooled to 0° C. and TEMPO (56 mg, 0.36 mmol, 2 mol %) was added, followed by the dropwise addition of NaOCl(aq) (60 ml, 1.1 eq). The mixture was then stirred for 1.5 hours at room temperature. The pH was then adjusted to 4 using aqueous hydrogen chloride (3N). The mixture was then extracted with 3×80 ml of ethyl acetate. The organic fractions were combined, dried over magnesium sulfate, filtered and then concentrated under vacuum to provide 2.0 grams of the crude product as a yellow solid.

Provenance & Evidence