Citric Acid → Indole-2-carboxylic acid

HRID 2378093Notes

Reaction equation

HRID 2378093 reaction equation
C([O:3][C:4]([C:6]1[N:7](C)[C:8]2[C:13]([CH:14]=1)=[CH:12][CH:11]=[CH:10][C:9]=2CC1CCN(C(OC(C)(C)C)=O)CC1)=[O:5])C.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.CO.O.[OH-].[K+]>[NH:7]1[C:8]2[C:13](=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:14]=[C:6]1[C:4]([OH:5])=[O:3]

Participants

5

Reactant 2

HCID 311Citric AcidHCID 58608315HCID 58608315, compound

Product 1

HCID 72899Indole-2-carboxylic acid

Reagents, catalysts & solvents 2

HCID 14797Potassium HydroxideSolventHCID 21892291Methanol tetrahydrofuran waterSolvent

Conditions

Temperature
60 °C

Procedure

The above indole-2-carboxylic acid ethyl ester intermediate was dissolved in THF/MeOH/H2O (3:1:1) and 1 mL of 1N KOH solution. The mixture was heated at 60° C. for 4 h. The mixture was then cooled to 0° C. and acidified with 10% citric acid to about pH 4. The mixture was extracted with EtOAc, dried and concentrated to afford 0.32 g of the indole-2-carboxylic acid intermediate.

Workup

  1. temperatureThe mixture was then cooled to 0° C.
  2. extractionThe mixture was extracted with EtOAc
  3. customdried
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-cc52c2141fd047c3aed7ee0cc3437ea2
Source dataset
uspto-grants-2008_12
Patent number
US07470692B2

Reaction notes

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