Ammonium formate → Ethyl 5-amino-1-ethyl-1H-indole-2-carboxylate

HRID 1455822Notes

Reaction equation

HRID 1455822 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[N:7]([CH2:18][CH3:19])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([N+:15]([O-])=O)=[CH:10][CH:9]=2)=[O:5])[CH3:2].C([O-])=O.[NH4+]>CCO.C(O)CC.[OH-].[Pd+2].[OH-]>[CH2:1]([O:3][C:4]([C:6]1[N:7]([CH2:18][CH3:19])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([NH2:15])=[CH:10][CH:9]=2)=[O:5])[CH3:2]

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 12148796ethyl 1-ethyl-5-nitro-1H-indole-2-carboxylate

Product 1

HCID 12148797Ethyl 5-amino-1-ethyl-1H-indole-2-carboxylateYield 90.2%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 9793718EtOH n-PrOHSolvent

Procedure

The 1-ethyl-5-nitro-1H-indole-2-carboxylic acid ethyl ester (59, 19.1 mmol) of step (a) was dissolved in EtOH/n-PrOH (100 mL, 1/1). Palladium hydroxide (1.14 g) and ammonium formate (3.92 g, 62.2 mmol) were added to the above solution. The mixture was heated to reflux for 2 hours. The reaction mixture was cooled to room temperature and the catalyst was filtered off through Celite. The solvent was removed under reduced pressure. The crude product was dissolved in dichloromethane (300 mL) and washed with NaHCO3 (150 ml×2). The organic layer was collected, dried (Na2SO4) and evaporated. The crude product was purified by chromatography to furnish the desired product (4 g, 90%).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2 hours
  3. filtrationthe catalyst was filtered off through Celite
  4. customThe solvent was removed under reduced pressure
  5. dissolutionThe crude product was dissolved in dichloromethane (300 mL)
  6. washwashed with NaHCO3 (150 ml×2)
  7. customThe organic layer was collected
  8. dry with materialdried (Na2SO4)
  9. customevaporated
  10. customThe crude product was purified by chromatography

Sources & evidence

ORD record
ord-0b7a1fdb9017478b9da07b6aa7c15383
Source dataset
uspto-grants-2009_01
Patent number
US07482368B2

Reaction notes

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