Ethanol → Ethyl 1H-indole-6-carboxylate

HRID 1371858Notes

Reaction equation

HRID 1371858 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
  7. dry with materialdry (Na2SO4)
  8. concentrationconcentrate to residue
  9. customChromatograph the residue on silica gel eluting with chloroform to give
  10. customafter evaporation

Sources & evidence

ORD record
ord-f4a1813bcb094efea40bd8acde8bfec0
Source dataset
uspto-grants-2007_01
Patent number
US07157488B2

Reaction notes

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