Formaldehyde → 3-Bromo-2-hydroxybenzaldehyde

Triethylamine (72 ml, 520 mmol) was added over 10 minutes to a suspension of paraformaldehyde (23.4 g, 780 mmol) and dry magnesium dichloride (49.5 g, 520 mmol, Aldrich; CAS 7786-30-3) in THF (1 liter) under nitrogen at room temperature. The resulting mixture was stirred for 20 min, then 2-bromophenol (45 g, 260 mmol) was added over 5 minutes via syringe. The resulting mixture was stirred under gentle reflux for 6 h then cooled to room temperature. The solution was left over the weekend and then diluted with diethylether (500 ml). The organic phase was washed with a 2N hydrochloric acid (500 ml) and the two phases were separated. The insoluble material was filtered off and the organic phase was washed twice with 2N hydrochloric acid (500 ml) then five times with water (100 ml), dried over magnesium sulphate and concentrated in vacuo to give the title compound as a colourless solid (46.5 g). MS (ES) C7H579BrO2 requires 200 found 199 [M−H]+.

1. stirringThe resulting mixture was stirred
2. temperatureunder gentle reflux for 6 h
3. waitThe solution was left over the weekend
4. washThe organic phase was washed with a 2N hydrochloric acid (500 ml)
5. customthe two phases were separated
6. filtrationThe insoluble material was filtered off
7. washthe organic phase was washed twice with 2N hydrochloric acid (500 ml)
8. dry with materialfive times with water (100 ml), dried over magnesium sulphate
9. concentrationconcentrated in vacuo

ORD record

ord-a925e349a9b249ed943c8f97d4ae68a8

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08222245B2