Ethyl Acetate → 2-methyl-1H-indol-7-ol

HRID 480577

Reaction equation

HRID 480577 reaction equation
[CH3:1][C:2]1[NH:3][C:4]2[C:9]([CH:10]=1)=[CH:8][CH:7]=[CH:6][C:5]=2[O:11]C.B(Br)(Br)Br.CCOC(C)=O>C(Cl)Cl>[CH3:1][C:2]1[NH:3][C:4]2[C:9]([CH:10]=1)=[CH:8][CH:7]=[CH:6][C:5]=2[OH:11]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 25134Boron tribromideHCID 3266147-methoxy-2-methyl-1H-indole

Product 1

HCID 187652222-methyl-1H-indol-7-olYield 99%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 2-methyl-7-methoxy indole (814 mg, 5.0 mmol) in CH2Cl2 (20 mL) at 0° C. was added BBr3 (15 mL, 15 mmol, 1M in CH2Cl2), and then the ice bath was removed and stirring was continued for 3 h. Ice was added and the reaction mixture diluted with water (30 mL). The aqueous layer was extracted with EtOAc (3×100 mL), dried over Na2SO4, filtered, and concentrated in vacuo. The residue was purified via passage through a short silica gel column (20% then 50% EtOAc/hex) to afford 2-methyl-7-hydroxy indole as an unstable solid (99% yield).

Workup

  1. customthe ice bath was removed
  2. additionIce was added
  3. additionthe reaction mixture diluted with water (30 mL)
  4. extractionThe aqueous layer was extracted with EtOAc (3×100 mL)
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified via passage through a short silica gel column (20%

Sources & evidence

ORD record
ord-9c7201aa7a1547a3b6a4cd2ee8ac00f5
Source dataset
uspto-grants-2003_11
Patent number
US06653304B2

Linked notes

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