4-Hydroxy-3-methoxy-5-(trifluoromethyl)benzaldehyde → 4-Hydroxy-3-methoxy-5-(trifluoromethyl)benzoic acid

Participants

Reaction Steps

A suspension of 4-hydroxy-3-methoxy-5-(trifluoromethyl)benzaldehyde (1.03 g, 4.68 mmol) and Oxone™ (3.45 g, 5.61 mmol) in DMF (10 mL) was stirred at RT for 2 h. The reaction mixture was diluted with EtOAc (40 mL) and the solution was washed sequentially with 1M HCl (40 mL) and brine (4×40 mL). The solvent was removed in vacuo and the residue was purified by silica gel chromatography (80 g, 0-10% MeOH in DCM) to afford 4-hydroxy-3-methoxy-5-(trifluoromethyl)benzoic acid (4) (392 mg, 35%) as a white solid: m/z 235 [M−H]− (ES−); 1H NMR (400 MHz, DMSO-d6) δ: 13.01 (1H, br s), 10.74 (1H, br s), 7.68 (2H, dd), 3.92 (3H, s).

Provenance & Evidence