Bromide ion → 3-Bromo-1h-indole

HRID 278396Notes

Reaction equation

HRID 278396 reaction equation
[Br-:1].COC1C=CC(C(O)C2C=CC(OC)=CC=2)=CC=1.[C:20]1([CH3:30])[CH:25]=[CH:24][C:23](S(O)(=O)=O)=[CH:22][CH:21]=1.C[N:32]1[CH2:36]CCC1=O>C1C=CC=CC=1.C(OCC)(=O)C>[Br:1][C:30]1[C:20]2[C:25](=[CH:24][CH:23]=[CH:22][CH:21]=2)[NH:32][CH:36]=1

Participants

7

Reactant 4

HCID 259Bromide ionHCID 6101p-Toluenesulfonic acidHCID 13387N-methyl-2-pyrrolidoneHCID 69768p,p'-Dimethoxybenzhydryl alcohol

Product 1

HCID 27632773-Bromo-1h-indoleYield 87%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of the above bromide (1.09 g, 2.8 mmol) in benzene (60 mL) and N-methylpyrrolidinone (6 mL) was added 4,4′-dimethoxybenzhydrol (818 mg, 3.4 mmol) and p-toluenesulfonic acid (532 mg, 2.8 mmol), and the mixture was heated to reflux. After 24 hours the reaction was cooled to room temperature and diluted with ethyl acetate (200 mL). The organic layer was washed with NaHCO3 (2×), H2O (2×), and brine(2×). The organic layer was dried over anhydrous MgSO4, filtered and solvent was removed in vacuo. The crude material was purified via column chromatography (10% EtOAc-hexane) to provide the desired DMB protected 3-bromo indole derivative (1.5 g, 2.4 mmol, 87% yield) as an orange solid: (MS m/z (M+H) 615, 617).

Workup

  1. temperaturethe mixture was heated to reflux
  2. washThe organic layer was washed with NaHCO3 (2×), H2O (2×), and brine(2×)
  3. dry with materialThe organic layer was dried over anhydrous MgSO4
  4. filtrationfiltered
  5. customsolvent was removed in vacuo
  6. customThe crude material was purified via column chromatography (10% EtOAc-hexane)
  7. customto provide the desired DMB

Sources & evidence

ORD record
ord-9bd2e99fc12a412c8570c5e815271937
Source dataset
uspto-grants-2002_03
Patent number
US06359130B1

Reaction notes

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