Dimethylformamide → Methyl 1-ethyl-3-formyl-1H-indole-6-carboxylate

HRID 506009Notes

Reaction equation

HRID 506009 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:13]=[C:12]2[C:8]([CH:9]=[CH:10][N:11]2[CH2:14][CH3:15])=[CH:7][CH:6]=1)=[O:4].O=P(Cl)(Cl)Cl.[OH-].[Na+].CN([CH:26]=[O:27])C>>[CH3:1][O:2][C:3]([C:5]1[CH:13]=[C:12]2[C:8]([C:9]([CH:26]=[O:27])=[CH:10][N:11]2[CH2:14][CH3:15])=[CH:7][CH:6]=1)=[O:4]

Participants

5

Reactant 4

HCID 6228Dimethylformamide2×HCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 22467242HCID 22467242, compound

Product 1

HCID 59425156Methyl 1-ethyl-3-formyl-1H-indole-6-carboxylateYield 96%

Procedure

1-Ethyl-1H-indole-6-carboxylic acid methyl ester (900 mg, 4.45 mmol) is dissolved in DMF (3.3 mL). This is added dropwise to an ice-cold solution of POCl3 (430 μL, 4.5 mmol) in DMF (1.5 mL). The reaction mixture is stirred at room temperature for 90 minutes. The reaction mixture is then treated with 6N NaOH (3.5 ml). The mixture is then partitioned between H2O and ethyl acetate. Purification by silica gel chromatography (5-10% EtOAc/CH2Cl2) yields 1-ethyl-3-formyl-1H-indole-6-carboxylic acid methyl ester (985 mg, 96%) as a white solid.

Workup

  1. customThe mixture is then partitioned between H2O and ethyl acetate
  2. customPurification by silica gel chromatography (5-10% EtOAc/CH2Cl2)

Sources & evidence

ORD record
ord-0b365ffb5bf94838bad4faacd80a2252
Source dataset
uspto-grants-2010_08
Patent number
US07781478B2

Reaction notes

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