Formaldehyde → 3-Bromo-2-hydroxybenzaldehyde

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).

1. temperatureThe mixture was heated to
2. temperaturea gentle reflux for 1 to 3 hours
3. temperaturecooled
4. customthe ether layer separated
5. washThe ether layer was washed with water, brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated by evaporation
8. customProduct purified from the residue by chromatography on silica gel employing 30% ethyl acetate/hexanes

ORD record

ord-469a9b2e2d354f3eb8ff6091581a2dee

Source dataset

uspto-grants-2015_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09162986B2