Hydrogen Bromide → 2,3-Dihydroxybenzaldehyde

HRID 260156Notes

Reaction equation

HRID 260156 reaction equation
[O:1]=[CH:2][C:3]1[CH:11]=[CH:10][CH:9]=[C:6]([O:7]C)[C:4]=1[OH:5].Br>C(O)(=O)C>[OH:5][C:4]1[C:6]([OH:7])=[CH:9][CH:10]=[CH:11][C:3]=1[CH:2]=[O:1]

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 8991o-Vanillin

Product 1

HCID 905792,3-DihydroxybenzaldehydeYield 70.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

152.0 g (1.0 mol) of o-vanillin and 200 ml of azeotropic hydrobromic acid (47.5% strength) are stirred under reflux in 500 ml of glacial acetic acid for 2.5 hours. The acid mixture is then distilled off and the residue is subjected to fractional vacuum distillation. The redistilled fraction having a boiling point of 120°-125° C./12 mbar is purified by recrystallisation from 11 of heptane (hexane is also possible and is recovered). 97 g (70% of theory) of 2,3-dihydroxybenzaldehyde of melting point 105°-107° C. are obtained.

Workup

  1. distillationThe acid mixture is then distilled off
  2. distillationthe residue is subjected to fractional vacuum distillation
  3. customis purified by recrystallisation from 11 of heptane (hexane
  4. customis recovered)

Sources & evidence

ORD record
ord-e5d0bfd10d71477383b4344e1ce1e720
Source dataset
uspto-grants-1996_06
Patent number
US05525739

Reaction notes

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