Potassium Permanganate → 3-Carboxyphenylboronic acid

Participants

Reaction Steps

A solution of 3-formylphenylboronic acid (3.35 g, 22.34 mmol) (Lancaster) in a 1:1 mixture of distilled water-acetone (64 mL) was slowly treated with potassium permanganate (6.00 g, 37.98 mmol) in small portions. The dark reaction mixture was stirred at room temperature for 1 h and then filtered through a pad of Celite®. The pad of Celite® was washed with 200 mL of distilled water then washed with 200 mL of acetone. The filtrate was concentrated in vacuo to a volume of approximately 200 mL. The resulting aqueous filtrate was treated with concentrated hydrochloric acid until pH=1 and then cooled using an ice/water bath. The desired product precipitated upon cooling. The solid was filtered and washed well with cold distilled water to provide 3-carboxyphenylboronic acid as a cream-colored solid which was used without further purification. (Yield 1.95 g, 53%; mp 232-234° C.).

Provenance & Evidence