Boron tribromide → Ethyl 2-(3,5-dihydroxyphenyl)acetate

HRID 2253730Notes

Reaction equation

HRID 2253730 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]([CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH:6]=[C:7]([O:9]C)[CH:8]=1.B(Br)(Br)Br>C(Cl)Cl>[OH:2][C:3]1[CH:4]=[C:5]([CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13])[CH:6]=[C:7]([OH:9])[CH:8]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 11831071Ethyl 2-(3,5-dimethoxyphenyl)acetate

Product 1

HCID 579799Ethyl 2-(3,5-dihydroxyphenyl)acetate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of ethyl 3,5-dimethoxyphenylacetate (11.0 g, 52,32 mmol) in 200 ml of CH2Cl2 is added 75 ml (25 mmol, 1.4 eq) of 1.0M BBr3 in CH2Cl2. This is then refluxed for 36 hours. The mixture is concentrated in vacuo, then partitioned between EtOAc and HCl. The organics are dried (MgSO4) and concentrated in vacuo. This is then redissolved in EtOH and HCl is bubbled in for 5 minutes and then stirred overnight at room temperature. The mixture is concentrated in vacuo, then partitioned between EtOAc and saturated NaHCO3 solution. The organics are dried (MgSO4) and concentrated in vacuo. This is then chromatographed using silica gel and eluted with Et2O. The filtrate is concentrated in vacuo to obtain ethyl 3,5-dihydroxyphenylacetate which is confirmed by NMR and used directly in the next step.

Workup

  1. temperatureThis is then refluxed for 36 hours
  2. concentrationThe mixture is concentrated in vacuo
  3. custompartitioned between EtOAc and HCl
  4. dry with materialThe organics are dried (MgSO4)
  5. concentrationconcentrated in vacuo
  6. dissolutionThis is then redissolved in EtOH
  7. customHCl is bubbled in for 5 minutes
  8. concentrationThe mixture is concentrated in vacuo
  9. custompartitioned between EtOAc and saturated NaHCO3 solution
  10. dry with materialThe organics are dried (MgSO4)
  11. concentrationconcentrated in vacuo
  12. customThis is then chromatographed
  13. washeluted with Et2O
  14. concentrationThe filtrate is concentrated in vacuo

Sources & evidence

ORD record
ord-c7065849047242a28052ea490e068cca
Source dataset
uspto-grants-1993_08
Patent number
US05232948

Reaction notes

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