Ethanol → Ethyl indole-5-carboxylate

HRID 1666854Notes

Reaction equation

HRID 1666854 reaction equation
[C:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[CH:7]2)([OH:3])=[O:2].C(N1C=CN=C1)(N1[CH:19]=[CH:18]N=C1)=O.CCO.[H-].[Na+]>C1COCC1>[CH2:18]([O:2][C:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][CH:8]=[CH:7]2)=[O:3])[CH3:19]

Participants

6

Reactant 4

HCID 702EthanolHCID 24758Sodium hydrideHCID 682631,1'-CarbonyldiimidazoleHCID 742801H-Indole-5-Carboxylic Acid

Product 1

HCID 10987040Ethyl indole-5-carboxylateYield 127.7%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Combine 5-carboxyindole (4.8 g, 29.8 mmol) in 150 mL THF and carbonyldiimidazole (9.7 g, 59.6 mmol) and stir overnight at ambient temperature. Treat the reaction mixture with 25 mL EtOH and 1.2 g (29.8 mmol) of a 60% oil dispersion of NaH and stir for 2 hours. Concentration under vacuum gives a residue. Partition the residue between 150 mL EtOAc and 100 mL brine. Separate the layers, dry the organic layer over MgSO4, filter, and concentrated to an oil. Chromatograph on silica gel eluting with 1% MeOH in CHCl3 to give 7.2 g of an oil. Crystallize the oil from toluene gives the title compound: Analysis for C11H11NO2: calcd: C, 69.83; H, 5.86; N, 7.40. found: C, 69.82; H, 5.90; N, 7.38. ISMS 190 (M+1).

Workup

  1. concentrationConcentration under vacuum
  2. customgives a residue
  3. customPartition the residue between 150 mL EtOAc and 100 mL brine
  4. customSeparate the layers
  5. dry with materialdry the organic layer over MgSO4
  6. filtrationfilter
  7. concentrationconcentrated to an oil

Sources & evidence

ORD record
ord-df570588493d4a9e9d86f842cbf7ffcb
Source dataset
uspto-grants-2011_10
Patent number
US08044090B2

Reaction notes

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