Trifluoroacetic acid → 6-ethoxy-2-(4-nitro-phenyl)-1H-indole

HRID 502269Notes

Reaction equation

HRID 502269 reaction equation
C(OC([N:8]1[C:16]2[C:11](=[CH:12][CH:13]=[C:14]([O:17][CH2:18][CH3:19])[CH:15]=2)[CH:10]=[C:9]1[C:20]1[CH:25]=[CH:24][C:23]([N+:26]([O-:28])=[O:27])=[CH:22][CH:21]=1)=O)(C)(C)C.C(O)(C(F)(F)F)=O>C(Cl)Cl>[CH2:18]([O:17][C:14]1[CH:15]=[C:16]2[C:11]([CH:10]=[C:9]([C:20]3[CH:21]=[CH:22][C:23]([N+:26]([O-:28])=[O:27])=[CH:24][CH:25]=3)[NH:8]2)=[CH:12][CH:13]=1)[CH3:19]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 590304236-Ethoxy-2-(4-nitro-phenyl)-indole-1-carboxylic acid tert-butyl ester

Product 1

HCID 590304256-ethoxy-2-(4-nitro-phenyl)-1H-indoleYield 75.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 6-ethoxy-2-(4-nitro-phenyl)-indole-1-carboxylic acid tert-butyl ester (8.1 g, 21.2 mmol) in CH2Cl2 (8 mL) was added TFA (8 mL). This mixture was stirred at room temperature for 2 h and concentrated. The residue was diluted in EtOAc and washed with sat.aq. NaHCO3. The organic layer was concentrated and purified by silica gel chromatography (7:3 CH2Cl2/hexane, followed by 100% CH2Cl2) to provide 6-ethoxy-2-(4-nitro-phenyl)-1H-indole (4.5 g, 68%) as an orange-red solid.

Workup

  1. concentrationconcentrated
  2. additionThe residue was diluted in EtOAc
  3. washwashed with sat.aq
  4. concentrationThe organic layer was concentrated
  5. custompurified by silica gel chromatography (7:3 CH2Cl2/hexane, followed by 100% CH2Cl2)

Sources & evidence

ORD record
ord-bd8e7a3384764d07bec79146054ba744
Source dataset
uspto-grants-2010_08
Patent number
US07772271B2

Reaction notes

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