Boron tribromide → 2,3-Dichloro-4-hydroxybenzaldehyde

HRID 1721942Notes

Reaction equation

HRID 1721942 reaction equation
B(Br)(Br)Br.[Cl:5][C:6]1[C:13]([Cl:14])=[C:12]([O:15]C)[CH:11]=[CH:10][C:7]=1[CH:8]=[O:9]>C(Cl)Cl>[OH:15][C:12]1[CH:11]=[CH:10][C:7]([CH:8]=[O:9])=[C:6]([Cl:5])[C:13]=1[Cl:14]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 130156892,3-Dichloro-4-methoxybenzaldehyde

Product 1

HCID 5283802,3-Dichloro-4-hydroxybenzaldehydeYield 95.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 5.51 g of boron tribromide in methylene chloride is added dropwise to a solution of 2.05 g of 2,3-dichloro-4-methoxybenzaldehyde in methylene chloride. The mixture is stirred at room temperature for 4 hours, poured into ice-water and then extracted with ethyl acetate. The extract is washed with water, dried and evaporated to remove solvent. 10% hydrochloric acid and methanol are added to the residue and the mixture is stirred for 3 hours under ice-cooling and extracted with ethyl acetate again. The extract is washed with water, dried and evaporated to remove solvent. The residue is crystallized with isopropyl ether to give 1.82 g of 4-hydroxy-2,3-dichlorobenzaldehyde.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe extract is washed with water
  3. customdried
  4. customevaporated
  5. customto remove solvent
  6. addition10% hydrochloric acid and methanol are added to the residue
  7. stirringthe mixture is stirred for 3 hours under ice-
  8. temperaturecooling
  9. extractionextracted with ethyl acetate again
  10. washThe extract is washed with water
  11. customdried
  12. customevaporated
  13. customto remove solvent
  14. customThe residue is crystallized with isopropyl ether

Sources & evidence

ORD record
ord-1f648a54b604468fa02b3183750482df
Source dataset
uspto-grants-1989_08
Patent number
US04853404

Reaction notes

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