Tetrabutylammonium Fluoride → Methyl 6-chloro-1H-indole-5-carboxylate

HRID 1891017Notes

Reaction equation

HRID 1891017 reaction equation
[CH3:1][O:2][C:3](=[O:21])[C:4]1[CH:9]=[C:8](C#C[Si](C)(C)C)[C:7]([NH:16][C:17](=O)[CH3:18])=[CH:6][C:5]=1[Cl:20].[F-].C([N+](CCCC)(CCCC)CCCC)CCC>C1COCC1>[Cl:20][C:5]1[CH:6]=[C:7]2[C:8]([CH:18]=[CH:17][NH:16]2)=[CH:9][C:4]=1[C:3]([O:2][CH3:1])=[O:21]

Participants

4

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 11839199Methyl 4-(acetylamino)-2-chloro-5-[(trimethylsilyl)ethynyl]benzoate

Product 1

HCID 10727132Methyl 6-chloro-1H-indole-5-carboxylateYield 86%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of methyl-2-chloro-4-acetamido-5-(2-trimethylsilylethynyl)-benzoate (1.9 g, 5.9 mmol) in THF (15.0 mL) containing tetrabutyl ammonium fluoride (1.9 g, 6.0 mmol) was heated to reflux for 6 h under nitrogen. The reaction mixture was concentrated to dryness and the residue partitioned between ethyl acetate (25 mL) and water (25 mL). The organic layer was washed with water, dried (MgSO4) and concentrated to dryness. The residue was purified by silica gel flash chromatography using 25% ethyl acetate in heptane to afford the title compound as a light brown powder (0.98 g, 86%), m/z 210 (M+H).

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 6 h under nitrogen
  3. concentrationThe reaction mixture was concentrated to dryness
  4. customthe residue partitioned between ethyl acetate (25 mL) and water (25 mL)
  5. washThe organic layer was washed with water
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated to dryness
  8. customThe residue was purified by silica gel flash chromatography

Sources & evidence

ORD record
ord-21b2da86f2cd45298935188e6bc2caf6
Source dataset
uspto-grants-2013_08
Patent number
US08507499B2

Reaction notes

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