Boron tribromide → (6-Hydroxy-benzo[b]thiophen-3-yl)-acetic acid ethyl ester

HRID 490763Notes

Reaction equation

HRID 490763 reaction equation
[CH2:1]([O:3][C:4](=[O:17])[CH2:5][C:6]1[C:7]2[CH:14]=[CH:13][C:12]([O:15]C)=[CH:11][C:8]=2[S:9][CH:10]=1)[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([O:3][C:4](=[O:17])[CH2:5][C:6]1[C:7]2[CH:14]=[CH:13][C:12]([OH:15])=[CH:11][C:8]=2[S:9][CH:10]=1)[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 21816275Ethyl 2-(6-methoxybenzo[b]thiophen-3-yl)acetate

Product 1

HCID 57431998(6-Hydroxy-benzo[b]thiophen-3-yl)-acetic acid ethyl esterYield 97%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of (6-Methoxy-benzo[b]thiophen-3-yl)-acetic acid ethyl ester (2.4 g, 9.6 mmol) in methylene chloride (60 mL) is added BBr3 (1.0 M, heptane, 29.4 mL, 29.4 mmol) at −20˜−30° C. The reaction mixture is allowed to warm to room temperature over 2 hrs, and TLC indicated clean conversion. The reaction is quenched by ice water, extracted with methylene chloride, dried over sodium sulfate, concentrated. Column chromatography on silica gel eluted with hexanes/ethyl acetate yields the title compound (2.2 g).

Workup

  1. customThe reaction is quenched by ice water
  2. extractionextracted with methylene chloride
  3. dry with materialdried over sodium sulfate
  4. concentrationconcentrated
  5. washColumn chromatography on silica gel eluted with hexanes/ethyl acetate

Sources & evidence

ORD record
ord-e47afb3386974ea1af2ca517d08e2336
Source dataset
uspto-grants-2009_05
Patent number
US07528160B2

Reaction notes

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