Boron tribromide → 2-Chloro-4,6-dihydroxybenzaldehyde

HRID 1798051Notes

Reaction equation

HRID 1798051 reaction equation
[Cl:1][C:2]1[C:7]([CH:8]=[O:9])=[C:6]([O:10]C)[CH:5]=[C:4]([O:12]C)[CH:3]=1.B(Br)(Br)Br>ClCCl>[Cl:1][C:2]1[C:7]([CH:8]=[O:9])=[C:6]([OH:10])[CH:5]=[C:4]([OH:12])[CH:3]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 38651392-Chloro-4,6-dimethoxybenzaldehyde

Product 1

HCID 232948482-Chloro-4,6-dihydroxybenzaldehydeYield 58.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To the solution of 6-chloro-2,4-dimethoxy-benzaldehyde (8 g, 39.9 mmol) in dichloromethane (100 mL) was added boron tribromide (16 mL, 170 mmol) dropwise at −78° C. The reaction mixture was stirred overnight at room temperature and quenched by ice. The resulting mixture was extracted by EtOAc (2×50 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gal (EtOAc/PE=1:5) to give the title compound as a yellow powder (4 g. Yield: 58%). 1H NMR (400 MHz, DMSO-d6) δ12.11 (s, 1H), 11.33 (s, 1H), 10.08 (s, 1H), 6.52-6.53 (d, J=2.0 Hz, 1H), 6.27-6.28 (s, J=2.0 Hz, 1H) MS (ESI) m/z=173 [M+H]+.

Workup

  1. customquenched by ice
  2. extractionThe resulting mixture was extracted by EtOAc (2×50 mL)
  3. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  4. concentrationconcentrated in vacuo
  5. customThe residue was purified by column chromatography on silica gal (EtOAc/PE=1:5)

Sources & evidence

ORD record
ord-e84a8caad72a4f189e8ae4d5f79df69e
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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