Sodium Hydroxide → 3-bromo-1H-indole-2-carboxylic acid

HRID 2292700Notes

Reaction equation

HRID 2292700 reaction equation
[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[NH:4][C:3]=1[C:11]([O:13]CC)=[O:12].[OH-].[Na+]>CCO.O>[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[NH:4][C:3]=1[C:11]([OH:13])=[O:12]

Participants

5

Reactant 2

HCID 14798Sodium HydroxideHCID 4715017Ethyl 3-Bromoindole-2-carboxylate

Product 1

HCID 23256883-bromo-1H-indole-2-carboxylic acidYield 96.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A solution of ethyl 3-bromoindole-2-carboxylate (54.40 g, 203 mmol) in EtOH (600 ml) and water (50 ml) with NaOH (20.20 g, 505 mmol) was refluxed for 1 h. The mixture was cooled and the sodium salt of the title compound was removed by filtration. This was acidified (aqueous 3N HCl) and extracted with ethyl acetate. The organic extract was washed with water then brine, dried (sodium sulfate) and concentrated. Crystallization from ethyl acetate afforded the product (47.1 g, 88%). mp 201°-203° C.

Workup

  1. temperatureThe mixture was cooled
  2. customthe sodium salt of the title compound was removed by filtration
  3. extractionextracted with ethyl acetate
  4. extractionThe organic extract
  5. washwas washed with water
  6. dry with materialbrine, dried (sodium sulfate)
  7. concentrationconcentrated
  8. customCrystallization from ethyl acetate

Sources & evidence

ORD record
ord-3dbfb79717d441fd8d38915e8fbb7d05
Source dataset
uspto-grants-1997_11
Patent number
US05684032

Reaction notes

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