Hydrochloric Acid → 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylic acid

HRID 873350Notes

Reaction equation

HRID 873350 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:14]([O:16]C)=[O:15])[C:5]2[CH:6]=[CH:7][N:8]([CH:11]([CH3:13])[CH3:12])[C:9]=2[CH:10]=1.[OH-].[Na+].Cl>CO.O1CCCC1.O>[Br:1][C:2]1[CH:3]=[C:4]([C:14]([OH:16])=[O:15])[C:5]2[CH:6]=[CH:7][N:8]([CH:11]([CH3:13])[CH3:12])[C:9]=2[CH:10]=1

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium Hydroxide2×HCID 67466539methyl 6-bromo-1-isopropyl-1H-indole-4-carboxylate

Product 1

HCID 674686386-bromo-1-(1-methylethyl)-1H-indole-4-carboxylic acidYield 99%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of methyl 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylate (0.52 g, 1.756 mmol) in methanol (15 mL) and tetrahydrofuran (3 mL) was added 3 M NaOH (1.756 mL, 5.27 mmol) via syringe drop wise (over 2 min). The solution was maintained at RT for 2 h, at which time LCMS showed only 12% conversion to product. Then 1.5 mL 3 M NaOH was added and the solution was maintained at RT overnight. LCMS showed complete conversion to product. Removed volatiles in vacuo and dissolved the residue in water and slowly acidified with 1 M HCl (solids precipitated). Extracted with EtOAc (2×), combined organics and dried over MgSO4. Filtered and concentrated in vacuo to give 6-bromo-1-(1-methylethyl)-1H-indole-4-carboxylic acid (0.50 g, 1.737 mmol, 99% yield) as a white solid.

Workup

  1. temperaturethe solution was maintained at RT overnight
  2. extractionExtracted with EtOAc (2×)
  3. dry with materialdried over MgSO4
  4. filtrationFiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-24df208ab89447dc8759bbb3fbe02c9d
Source dataset
uspto-grants-2015_03
Patent number
US08975291B2

Reaction notes

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