Ethanol → Ethyl 1H-indole-6-carboxylate

HRID 1666799Notes

Reaction equation

HRID 1666799 reaction equation
[C:1]([C:4]1[CH:12]=[C:11]2[C:7]([CH:8]=[CH:9][NH:10]2)=[CH:6][CH:5]=1)([OH:3])=[O:2].OS(O)(=O)=O.[CH2:18](O)[CH3:19]>>[CH2:18]([O:2][C:1]([C:4]1[CH:12]=[C:11]2[C:7]([CH:8]=[CH:9][NH:10]2)=[CH:6][CH:5]=1)=[O:3])[CH3:19]

Participants

4

Reactant 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 5952301H-indole-6-carboxylic acid

Product 1

HCID 15205372Ethyl 1H-indole-6-carboxylate

Procedure

Combine 6-carboxy-1H-indole and ethanol (110 ml) and cool to 5° C. Add dropwise concentrated H2SO4 (96%, 11.08 ml) while keeping the temperature below 10° C. Heat to reflux. After 4 hours, cool and pour onto ice/water, adjust the pH to about pH 9 and extract with ethyl acetate. Combine the organic extracts, wash with brine, dry Na2SO4), then concentrate to residue. Chromatograph the residue on silica gel eluting with chloroform to give, after evaporation, the title compound: mp 72-75° C. MS (ACPI): m/e 189.9 (M+1).

Workup

  1. customthe temperature below 10° C
  2. temperatureHeat to reflux
  3. temperaturecool
  4. additionpour onto ice/water
  5. extractionextract with ethyl acetate
  6. washwash with brine, dry Na2SO4),
  7. concentrationthen concentrate to residue
  8. customChromatograph the residue on silica gel eluting with chloroform to give
  9. customafter evaporation

Sources & evidence

ORD record
ord-5f1768d41e614e369a550d8c1a8866e0
Source dataset
uspto-grants-2011_10
Patent number
US08044090B2

Reaction notes

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