Hydrochloric Acid → 3-Fluoro-4,5-dihydroxybenzaldehyde

Participants

Reaction Conditions

Reaction Steps

Anhydrous aluminum chloride (1.11 g, 8.2 mmol) was added to a solution of 3-fluoro-4-hydroxy-5-methoxy benzaldehyde (1.2 g; 6.8 mmol) in dry dichloromethane (16 ml) under an atmosphere of nitrogen. The reaction mixture was cooled down to 0° C., pyridine (2.5 ml; 31 mmol) was slowly added and the solution was heated to reflux and stirred for 24 h. The solution was cooled to 0° C. and 4M aqueous hydrochloric acid was added to the mixture until the pH was approximately 2. The organic phase was discarded and the water phase was extracted with ethyl ether (3×15 ml). The organic extracts were combined then dried over sodium sulfate and concentrated under vacuum to give 3-fluoro-4,5-dihydroxybenzaldehyde (0.904 g; 85% yield) as a yellow solid. 1H NMR (400 MHz, CD3OD) δ 9.68 (d, 1H), 7.17 (dd, 1H), 7.16 (br. s, 1H). MS (EI) for C7H5FO3: 157 (MH+).

Provenance & Evidence