Lithium Hydroxide → 4,6-dimethyl-1H-indole-2-carboxylic Acid

HRID 507327Notes

Reaction equation

HRID 507327 reaction equation
C([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[C:12]([CH3:15])[CH:11]=[C:10]([CH3:16])[CH:9]=2)=[O:5])C.[OH-].[Li+]>C(O)C>[CH3:15][C:12]1[CH:11]=[C:10]([CH3:16])[CH:9]=[C:8]2[C:13]=1[CH:14]=[C:6]([C:4]([OH:5])=[O:3])[NH:7]2

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 4714990ethyl 4,6-dimethyl-1H-indole-2-carboxylate

Product 1

HCID 34459014,6-dimethyl-1H-indole-2-carboxylic AcidYield 95.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 4,6-dimethyl-1H-indole-2-carboxylic acid ethyl ester (22 g, 0.1 mol) and lithium hydroxide (4.8 g, 0.2 mol) in 400 ml of ethanol was heated at reflux overnight. The solvent was removed under reduced pressure and the residue was dissolved in water and neutralized with 10% HCl to pH<3. The resulting precipitates were filtered and washed with water and dried in vacuo at 40° C. to give white solids (18 g, 95%). 1H NMR (DMSO-d6, 400 MHz): δ 12.73 (brs, 1H, exchangeable with D2O, NH), 11.55 (brs, 1H, exchangeable with D2O, NH), 7.06 (s, 1H), 7.03 (s, 1H), 6.69 (s, 1H), 2.44 (s, 3H), 2.35 (s, 3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight
  3. customThe solvent was removed under reduced pressure
  4. dissolutionthe residue was dissolved in water and neutralized with 10% HCl to pH<3
  5. customThe resulting precipitates
  6. filtrationwere filtered
  7. washwashed with water
  8. customdried in vacuo at 40° C.

Sources & evidence

ORD record
ord-0c44b5b082f8490b88e20f286dde305c
Source dataset
uspto-grants-2010_08
Patent number
US07786146B2

Reaction notes

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