Hydrochloric Acid → 4-Fluoro-2,3-dihydroxybenzaldehyde

Participants

Reaction Steps

Magnesium chloride (3.71 g, 33 mmol) was added portionwise at room temperature to a solution of 3-fluorocatechol (2 g, 15.6 mmol) in acetonitrile (20 mL), followed by triethylamine (13.4 mL, 97.5 mmol). Paraformaldehyde (3.16 g, 105.3 mmol) was then added to the stirred suspension and the mixture was heated at reflux for 5 hours. The mixture was cooled to room temperature then poured into a mixture of 5% HCl and TBME. The organic phase was separated, and the aqueous layer re-extracted with TBME. The combined organic extracts were washed with brine, dried over sodium sulphate and the solvent removed under reduced pressure. The crude mixture (˜1:1 starting material:product) was purified on normal silica in neat DCM followed by DCM/MeOH 96:4 and 90:10 to yield 478 mg of 28 still contaminated with 11.4% w/w of 3-fluorocatechol.

Provenance & Evidence