Boron tribromide → 5-Hydroxybenzofuran-2-carboxylic acid

HRID 1947466Notes

Reaction equation

HRID 1947466 reaction equation
C[O:2][C:3]1[CH:4]=[CH:5][C:6]2[O:10][C:9]([C:11]([OH:13])=[O:12])=[CH:8][C:7]=2[CH:14]=1.B(Br)(Br)Br.[NH4+].[Cl-]>C(Cl)Cl>[OH:2][C:3]1[CH:4]=[CH:5][C:6]2[O:10][C:9]([C:11]([OH:13])=[O:12])=[CH:8][C:7]=2[CH:14]=1

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 25517Ammonium ChlorideHCID 2886385-Methoxybenzofuran-2-carboxylic acid

Product 1

HCID 122089725-Hydroxybenzofuran-2-carboxylic acidYield 100%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a cooled (−78° C.) solution of 5-methoxy-benzofuran-2-carboxylic acid (5.0 g, 26.0 mmol) in DCM (100 mL) was added BBr3 (7.4 mL, 19.5 g, 78.0 mmol) and the reaction mixture was stirred (2 h). The reaction mixture was warmed (rt) and subsequently cooled (0° C.) and treated with saturated NH4Cl (100 mL). The resultant biphasic mixture was partitioned and the aqueous layer was extracted with EtOAc (3×100 mL), dried, filtered and concentrated in vacuo to afford the title compound (4.6 g, 100%).

Workup

  1. temperaturesubsequently cooled (0° C.)
  2. customThe resultant biphasic mixture was partitioned
  3. extractionthe aqueous layer was extracted with EtOAc (3×100 mL)
  4. customdried
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d948c84e079a41c683802ec4cebab464
Source dataset
uspto-grants-2013_03
Patent number
US08399465B2

Reaction notes

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