Water → 7-Fluoro-5-methyl-1H-indole

HRID 750541Notes

Reaction equation

HRID 750541 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-299b2eeb0aa54c4fbaaf0eb08e9d173b
Source dataset
uspto-grants-2008_07
Patent number
US07405219B2

Reaction notes

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