Boron tribromide → 1-Benzyl-2-ethyl-1H-indol-4-OL

HRID 988588Notes

Reaction equation

HRID 988588 reaction equation
[CH2:1]([C:3]1[N:4]([CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:5]2[C:10]([CH:11]=1)=[C:9]([O:12]C)[CH:8]=[CH:7][CH:6]=2)[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([C:3]1[N:4]([CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:5]2[C:10]([CH:11]=1)=[C:9]([OH:12])[CH:8]=[CH:7][CH:6]=2)[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 99432411-Benzyl-2-ethyl-4-methoxy-1H-indole

Product 1

HCID 98164161-Benzyl-2-ethyl-1H-indol-4-OLYield 54%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

3.1 g (11.7 mmol) of 2-ethyl-4-methoxy-1-(phenylmethyl)-1H-indole was O-demethylated by treating it with 48.6 mL of 1M BBr3 in methylene chloride with stirring at room temperature for 5 hours, followed by concentration at reduced pressure. The residue was dissolved in ethyl acetate, washed with brine and dried (MgSO4). After concentrating at reduced pressure, the residue was chromatographed on silica gel eluting with 20% EtOAc/hexane to give 1.58 g (54% yield) of 2-ethyl-4-hydroxy-1-(phenylmethyl)-1H-indole, mp, 86-90° C.

Workup

  1. concentrationfollowed by concentration at reduced pressure
  2. dissolutionThe residue was dissolved in ethyl acetate
  3. washwashed with brine
  4. dry with materialdried (MgSO4)
  5. concentrationAfter concentrating at reduced pressure
  6. customthe residue was chromatographed on silica gel eluting with 20% EtOAc/hexane

Sources & evidence

ORD record
ord-1fe3ec3c59c947ae97e9e7a051eb9a6b
Source dataset
uspto-grants-2003_10
Patent number
US06635670B2

Reaction notes

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