Trifluoroacetic acid → 2-ethyl-4-methoxy-1H-indole

HRID 1825159Notes

Reaction equation

HRID 1825159 reaction equation
C(OC(=O)[NH:7][C:8]1[CH:13]=[C:12](OC)[CH:11]=[CH:10][C:9]=1[CH2:16][C:17](=O)[CH2:18][CH3:19])(C)(C)C.[C:22](O)(C(F)(F)F)=[O:23]>C1COCC1>[CH2:18]([C:17]1[NH:7][C:8]2[C:9]([CH:16]=1)=[C:10]([O:23][CH3:22])[CH:11]=[CH:12][CH:13]=2)[CH3:19]

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 20767945[5-Methoxy-2-(2-oxo-butyl)-phenyl]-carbamic acid t-butyl Ester

Product 1

HCID 98556072-ethyl-4-methoxy-1H-indoleYield 73%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of [5-methoxy-2-(2-oxo-butyl)-phenyl]-carbamic acid t-butyl ester 73b (1.36 g, 4.65 mmole) in 10 ml THF was added 4 ml TFA. The reaction mixture was stirred at room temperature for 5 h, quenched with 50 ml H2O and extracted with EtOAc. The organic layer was dried over MgSO4 and concentrated. The residue was purified by flash column chromatography (10–15% EtOAc in hexane) to give pale yellow solid (1.36 g, 73%). 1H NMR (CDCl3) δ 7.75 (1H, bs), 7.49 (1H, d, J=8.6 Hz), 6.81 (1H, s), 6.73 (1H, d, J=8.6 Hz), 3.83 (3H, s), 2.75 (2H, q, J=7.5 Hz), 1.32 (3H, t, J=7.5 Hz). ESIMS (MH+): 272.10.

Workup

  1. customquenched with 50 ml H2O
  2. extractionextracted with EtOAc
  3. dry with materialThe organic layer was dried over MgSO4
  4. concentrationconcentrated
  5. customThe residue was purified by flash column chromatography (10–15% EtOAc in hexane)

Sources & evidence

ORD record
ord-60e92b7e59664f0997ebd90853d9be3b
Source dataset
uspto-grants-2006_05
Patent number
US07045528B2

Reaction notes

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