Formaldehyde → 3-Bromo-2-hydroxybenzaldehyde

Participants

Reaction Steps

2-Bromophenol (2 g, 11.5 mmol) was dissolved in anhydrous acetonitrile (25 mL) and the solution was charged with anhydrous (<1.5% water) magnesium chloride (4.4 g, 46 mmol) and dry triethylamine (12.5 mL, 86.3 mmol). The mixture was stirred for 5 minutes and paraformaldehyde (2.8 g, 92 mmol) was added. The mixture was heated to a gentle reflux for 1 to 3 hours and then cooled. The mixture was poured onto an ether/5% citric acid mixture and the ether layer separated. The ether layer was washed with water, brine, dried over anhydrous sodium sulfate and concentrated by evaporation. Product purified from the residue by chromatography on silica gel employing 30% ethyl acetate/hexanes to give 3-bromo-2-hydroxybenzaldehyde (1.6 g).

Provenance & Evidence