Sulfuric Acid → methyl 1H-indole-5-carboxylate

HRID 634633Notes

Reaction equation

HRID 634633 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][C:6]([C:10]([OH:12])=[O:11])=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.S(=O)(=O)(O)O.[C:18](=O)([O-])O.[Na+]>CO>[CH3:18][O:11][C:10]([C:6]1[CH:5]=[C:4]2[C:9](=[CH:8][CH:7]=1)[NH:1][CH:2]=[CH:3]2)=[O:12]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 742801H-Indole-5-Carboxylic AcidHCID 516892Sodium Bicarbonate

Product 1

HCID 2737635methyl 1H-indole-5-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A methanol (200 ml) solution of indole-5-carboxylic acid (5.15 g) was refluxed in the presence of concentrated sulfuric acid (3 ml) at 85° C. for 4.5 hours. After the reaction, saturated aqueous sodium hydrogencarbonate solution was added at 0° C. and the mixture was extracted with ethyl acetate. The organic phase was washed with brine and dried over magnesium sulfate, then the solvent was evaporated in vacuo and the residue was purified by silica gel column chromatography to obtain indole-5-carboxylic acid methyl ester (4.8 g).

Workup

  1. additionwas added at 0° C.
  2. extractionthe mixture was extracted with ethyl acetate
  3. washThe organic phase was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. customthe solvent was evaporated in vacuo
  6. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-7dc1dac686594c4f8276e70baf4869e0
Source dataset
uspto-grants-2001_02
Patent number
US06184238B2

Reaction notes

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