Hydrochloric Acid → 5-bromo-6-methyl-1H-indole

HRID 1754962Notes

Reaction equation

HRID 1754962 reaction equation
COC(=O)[NH:4][C:5]1[CH:10]=[C:9]([CH3:11])[C:8]([Br:12])=[CH:7][C:6]=1[C:13]#[C:14][Si](C)(C)C.[O-]CC.[Na+].Cl>C(O)C.[Cl-].[Na+].O>[Br:12][C:8]1[CH:7]=[C:6]2[C:5](=[CH:10][C:9]=1[CH3:11])[NH:4][CH:14]=[CH:13]2

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 2723922Sodium ethoxideHCID 66816224(4-Bromo-5-methyl-2-trimethylsilanylethynyl-phenyl)-carbamic acid methyl ester

Product 1

HCID 247292415-bromo-6-methyl-1H-indoleYield 66.1%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 57417360Sodium chloride; waterSolvent

Conditions

Temperature
70 °C

Procedure

(4-Bromo-5-methyl-2-trimethylsilanylethynyl-phenyl)-carbamic acid methyl ester (506 mg, 1.49 mmol) was dissolved in ethanol (6 ml). Sodium ethoxide (20% solution in ethanol, 1.17 ml, 2.97 mmol) was added and the mixture was stirred at 70° C. overnight. The reaction solution was poured into ice water, and 1 N hydrochloric acid and saturated brine were added to this mixture, followed by extraction with ethyl acetate. The organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (n-hexane-ethyl acetate) to give 5-bromo-6-methyl-1H-indole (207 mg, 66%).

Workup

  1. additionwere added to this mixture
  2. extractionfollowed by extraction with ethyl acetate
  3. washThe organic layer was washed with water and saturated brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe resulting residue was purified by silica gel column chromatography (n-hexane-ethyl acetate)

Sources & evidence

ORD record
ord-ffee61e408fd43899e86637587047854
Source dataset
uspto-grants-2015_10
Patent number
US09169254B2

Reaction notes

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