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

HRID 2307518Notes

Reaction equation

HRID 2307518 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-fa08b791a3a74f43bb6c143a653d2120
Source dataset
uspto-grants-2004_12
Patent number
US06831095B1

Reaction notes

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