Water → 7-Fluoro-5-methyl-1H-indole

HRID 733015Notes

Reaction equation

HRID 733015 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH3:13])[CH:5]=[C:6]2[C:10]=1[NH:9][C:8](=O)[C:7]2=O.[H-].[H-].[H-].[H-].[Li+].[Al+3].O.[OH-].[Na+]>C1COCC1>[F:1][C:2]1[CH:3]=[C:4]([CH3:13])[CH:5]=[C:6]2[C:10]=1[NH:9][CH:8]=[CH:7]2

Participants

6

Reactant 4

HCID 962Water2×HCID 14798Sodium HydroxideHCID 167875657-Fluoro-5-methyl-1H-indole-2,3-dioneHCID 21226445Aluminium lithium hydride

Product 1

HCID 218747727-Fluoro-5-methyl-1H-indoleYield 41%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 7-fluoro-5-methylisatin (1.68 g, 9.43 mmol) in dry THF (50 mL) was added slowly to an ice cold, stirred suspension of LiAlH4 (1.18 g, 31 mmol) in dry THF (50 mL), refluxed for 2 h, cooled to room temperature then treated sequentially with H2O (1.2 mL), 15% NaOH (1.2 mL) and H2O (3 mL). The solution was filtered through a pad of Celite, washing the filter cake thoroughly with THF, the deep blue filtrate was concentrated in vacuo and purified by chromatography [SiO2; iso-Hexane:EtOAc (9:1)] to give the title compound (480 mg, 41%) as a pale blue oil; NMR δH (CDCl3) 8.19 (1H, br s), 7.21-7.16 (2H, m), 6.74 (1H, d, J 12.0 Hz), 6.51-6.46 (1H, m) and 2.42 (3H, s).

Workup

  1. temperaturerefluxed for 2 h
  2. filtrationThe solution was filtered through a pad of Celite
  3. washwashing the filter cake thoroughly with THF
  4. concentrationthe deep blue filtrate was concentrated in vacuo
  5. custompurified by chromatography [SiO2; iso-Hexane:EtOAc (9:1)]

Sources & evidence

ORD record
ord-205bf91438c4464bb82125f930a68996
Source dataset
uspto-grants-2009_09
Patent number
US07589097B2

Reaction notes

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