Water → 1-Methyl-3-(1-methylethoxy)-5-(phenylmethoxy)-1H-indole-2-carboxylic acid

HRID 21587

Reaction equation

HRID 21587 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][C:7]([O:11][CH2:12][C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)=[CH:8][CH:9]=2)[C:4]([O:19][CH:20]([CH3:22])[CH3:21])=[C:3]1[C:23]([O:25]C(C)(C)C)=[O:24].[OH-].[Na+].O>COCCO>[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][C:7]([O:11][CH2:12][C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)=[CH:8][CH:9]=2)[C:4]([O:19][CH:20]([CH3:22])[CH3:21])=[C:3]1[C:23]([OH:25])=[O:24]

Participants

5

Reactant 3

HCID 962Water2×HCID 14798Sodium HydroxideHCID 108345245-Benzyloxy-3-isopropoxy-1-methyl-1H-indole-2-carboxylic acid tert-butyl ester

Product 1

HCID 105690841-Methyl-3-(1-methylethoxy)-5-(phenylmethoxy)-1H-indole-2-carboxylic acidYield 88.4%

Reagents, catalysts & solvents 1

HCID 80192-MethoxyethanolSolvent

Procedure

A suspension of 1,1-dimethylethyl 1-methyl-3(1-methylethoxy)-5-(phenylmethoxy)-1H-indole-2-carboxylate (5.6 g, 14 mmol) in 80 mL of 2-methoxyethanol is treated with a solution of 50% aqueous sodium hydroxide (5.0 g, 63 mmol) followed by the addition of 15 mL of water. The mixture is stirred at reflux for 3 hours, then cooled and added to 700 mL of water. The mixture is heated on a hot plate until nearly one phase and filtered hot. The warm filtrate is immediately treated with 50 mL of 4.0N HCl. After cooling to room temperature, followed by 1 hour in an ice bath, the precipitated solid is filtered and washed with 25% methanol in water to give 4.2 g (88%) of product suitable for further synthesis. A sample recrystallized from ethyl acetate-hexane has mp 136° C.-dec.

Workup

  1. temperatureat reflux for 3 hours
  2. temperaturecooled
  3. temperatureThe mixture is heated on a hot plate until nearly one phase
  4. filtrationfiltered hot
  5. additionThe warm filtrate is immediately treated with 50 mL of 4.0N HCl
  6. filtrationthe precipitated solid is filtered
  7. washwashed with 25% methanol in water

Sources & evidence

ORD record
ord-9619e7daf99446a5b0dceda6fd6203e7
Source dataset
uspto-grants-1995_06
Patent number
US05424329

Linked notes

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