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

HRID 369732Notes

Reaction equation

HRID 369732 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-3da0305bbcb641cabbdd9f2b9c6aa3ab
Source dataset
uspto-grants-2000_10
Patent number
US06140327

Reaction notes

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