Lithium hydroxide, monohydrate → 4-Cyano-1H-indole-2-carboxylic acid

HRID 62651Notes

Reaction equation

HRID 62651 reaction equation
[C:1]([C:3]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:4]=1[CH:5]=[C:6]([C:12]([O:14]CC)=[O:13])[NH:7]2)#[N:2].O[Li].O>C(O)C>[C:1]([C:3]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:4]=1[CH:5]=[C:6]([C:12]([OH:14])=[O:13])[NH:7]2)#[N:2]

Participants

4

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 53419488Ethyl 4-cyano-1H-indole-2-carboxylate

Product 1

HCID 824059494-Cyano-1H-indole-2-carboxylic acidYield 87.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of ethyl 4-cyano-1H-indole-2-carboxylate (I-3a: 330 mg, 1.542 mmol) in ethanol (10 mL) was added LiOH.H2O (129 mg, 3.08 mmol) and the mixture was refluxed for 16 h. The solvent was evaporated under reduced pressure and the residue diluted with water (10 mL). The aqueous layer was acidified with 10% aq. HCl solution to pH 6.0 and the precipitated solid was filtered. The residue was washed with water and dried under vacuum to afford 250 mg (87%) of 4-cyano-1H-indole-2-carboxylic acid (I-3b) as an off-white solid.

Workup

  1. temperaturethe mixture was refluxed for 16 h
  2. customThe solvent was evaporated under reduced pressure
  3. additionthe residue diluted with water (10 mL)
  4. filtrationthe precipitated solid was filtered
  5. washThe residue was washed with water
  6. customdried under vacuum

Sources & evidence

ORD record
ord-d11bd53159264448a39ada489d103b3f
Source dataset
uspto-grants-2016_09
Patent number
US09447039B2

Reaction notes

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