Sodium Hydroxide → 5-ethyl-2,3-dihydro-1H-indole

HRID 2189563Notes

Reaction equation

HRID 2189563 reaction equation
C1(S([N:10]2[C:18]3[C:13](=[CH:14][C:15]([CH2:19][CH3:20])=[CH:16][CH:17]=3)[CH2:12][CH2:11]2)(=O)=O)C=CC=CC=1.[OH-].[Na+]>Br>[CH2:19]([C:15]1[CH:14]=[C:13]2[C:18](=[CH:17][CH:16]=1)[NH:10][CH2:11][CH2:12]2)[CH3:20]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 141129525-Ethyl-1-(phenylsulfonyl)indoline

Product 1

HCID 167881195-ethyl-2,3-dihydro-1H-indoleYield 34%

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

A mixture of 1-benzenesulfonyl-5-ethyl-2,3-dihydro-1H-indole (15 g, 0.05 mol) in HBr (48%, 162 mL) was heated at reflux for 6 h. The mixture was basified with sat. NaOH solution to pH 9 and extracted with ethyl acetate. The organic layer was washed with brine, dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel to give 5-ethyl-2,3-dihydro-1H-indole (2.5 g, 32%).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 6 h
  3. extractionextracted with ethyl acetate
  4. washThe organic layer was washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by column chromatography on silica gel

Sources & evidence

ORD record
ord-f946ff8adbcd452d9192fd197c330e27
Source dataset
uspto-grants-2012_12
Patent number
US08324242B2

Reaction notes

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