Sodium Hydroxide → 4-Fluoro-3,5-diisopropoxybenzoic acid

Participants

Reaction Steps

TEMPO (12 mg, 79 μmol) was added to (4-fluoro-3,5-diisopropoxyphenyl)methanol (7) (382 mg, 1.58 mmol) in a mixture of MeCN (10 mL) and sodium phosphate buffer at 35° C. Sodium chlorite (285 mg, 3.15 mmol) in water (5 mL) and sodium hypochlorite (97 μl, 1.6 mmol) were added cautiously (portionwise, 20% of one then the other every 10 min until the addition was complete). Once the reaction was complete the mixture was basified to pH 9 by the addition of NaOH (15 mL). Sodium sulfite (aq., 20 mL) was added and the aqueous mixture was washed with diethyl ether (50 mL). The aqueous layer was acidified by the addition of 4M HCl and the product was extracted into EtOAc (50 mL). The organic solution was dried over MgSO4, filtered and the solvent was removed in vacuo. The residue was purified by silica gel chromatography (12 g, 0-40% EtOAc in isohexane) to afford 4-fluoro-3,5-diisopropoxybenzoic acid (8) (50 mg, 12%) as a white solid: m/z 255 [M−H]− (ES−).

Provenance & Evidence