Hydrogen Bromide → 2,3-Dihydroxybenzaldehyde

Participants

Reaction Steps

Into a 500 ml round bottom flask fitted with a nitrogen inlet, condenser, and a magnetic stirring bar were placed o-vanillin (50 g, 330 mmol), 200 ml glacial acetic acid, and 60 ml of 48% hydrobromic acid. The mixture was heated to reflux and allowed to stir for 18 hours. The solvent was distilled off and the residue was taken up in methanol and filtered. The filtrate was concentrated and the residue taken up in methylene chloride. This solution was washed three times with sodium bicarbonate, twice with brine, dried over sodium sulfate, filtered, and concentrated. The crude product was dissolved in 0-2% methanol in methylene chloride and chromatographed (100:10:1 methylene chloride:methanol:ammonium hydroxide) to give 12.49g. of subtitled product (27%) which was used directly in the next step.

Provenance & Evidence