Sodium Hydroxide → 4-Bromo-3-fluorobenzoic acid

Participants

Reaction Steps

A solution of 4-bromo-3-fluorotoluene (35 g) and sodium hydroxide (7.7 g) in pyridine and water was stirred and heated to reflux. Potassium permanganate (123 g) was added to the mixture over 2 hours. The resulting suspension was heated at reflux for a further 3 hours. The mixture was filtered hot through hyflo silica. The silica was washed with boiling water, followed by ethyl acetate. The cooled aqueous layer was acidified to pH1 with concentrated hydrochloric acid and extracted with ethyl acetate. The organic extract was washed with water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue triturated with petroleum spirit (b.p. 60°-80° C.) to give 4-bromo-3-fluorobenzoic acid as a white solid (21.25 g), m.p. 213°-215° C.

Provenance & Evidence