Boron tribromide → Ethyl 5-hydroxybenzofuran-2-carboxylate

HRID 493168Notes

Reaction equation

HRID 493168 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:14]=[CH:13][C:12]([O:15]C)=[CH:11][C:9]=2[CH:10]=1)=[O:5])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:14]=[CH:13][C:12]([OH:15])=[CH:11][C:9]=2[CH:10]=1)=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 5212832-Benzofurancarboxylic acid, 5-methoxy-, ethyl ester

Product 1

HCID 22228632Ethyl 5-hydroxybenzofuran-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

The above prepared 5-methoxy-benzofuran-2-carboxylic acid ethyl ester (8.10 g, 36.8 mmol) was dissolved in 250 mL of CH2Cl2, cooled to 0° C., and treated with BBr3 (73.6 mL of 1M solution in CH2Cl2, 2 eq.). After 2 h, the reaction mixture was carefully poured onto crashed ice, twofold extracted with CH2Cl2, washed with brine, dried over magnesium sulfate, and evaporated to dryness. Ensuing flash chromatography (SiO2, hexane/AcOEt=8/2) delivered then 5.63 g of the title compound as off-white crystals.

Workup

  1. additionthe reaction mixture was carefully poured
  2. extractiontwofold extracted with CH2Cl2
  3. washwashed with brine
  4. dry with materialdried over magnesium sulfate
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-fae4dd29020d4c56ba37b03c148f2d48
Source dataset
uspto-grants-2009_05
Patent number
US07534788B2

Reaction notes

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