Lithium Hydroxide → 5-bromo-4-methyl-1H-indole-2-carboxylic acid

HRID 2181195Notes

Reaction equation

HRID 2181195 reaction equation
C([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[C:12]([CH3:15])[C:11]([Br:16])=[CH:10][CH:9]=2)=[O:5])C.[OH-].[Li+]>O1CCOCC1>[Br:16][C:11]1[C:12]([CH3:15])=[C:13]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6]([C:4]([OH:5])=[O:3])=[CH:14]2

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 695631205-bromo-4-methyl-1H-indole-2-carboxylic acid ethyl ester

Product 1

HCID 224856945-bromo-4-methyl-1H-indole-2-carboxylic acidYield 99.8%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

5.37 g (19.0 mmol) of 5-bromo-4-methyl-1H-indole-2-carboxylic acid ethyl ester were dissolved in 150 ml of dioxane; then, 38.1 ml (38.1 mmol) of a lithium hydroxide solution (1 molar in water) were added and the reaction mixture was stirred for 60 hours at room temperature. After evaporation of the solvents, the residue was dissolved in dichloromethane; water was added and the pH adjusted to pH 2-3; then, the mixture was extracted 3 times with dichloromethane. The combined organic phases were washed with water, dried over magnesium sulfate and evaporated to give 4.82 g of crude 5-bromo-4-methyl-1H-indole-2-carboxylic acid as off-white solid.

Workup

  1. customAfter evaporation of the solvents
  2. dissolutionthe residue was dissolved in dichloromethane
  3. additionwater was added
  4. extractionthen, the mixture was extracted 3 times with dichloromethane
  5. washThe combined organic phases were washed with water
  6. dry with materialdried over magnesium sulfate
  7. customevaporated

Sources & evidence

ORD record
ord-3e806a8ca6a34e33a9a8e26753c39d83
Source dataset
uspto-grants-2005_05
Patent number
US06890947B2

Reaction notes

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