Benzyl Bromide → 5-Benzyloxy-3-ethoxycarbonyl-2-methylindole

HRID 16632Notes

Reaction equation

HRID 16632 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6]([CH3:11])=[C:5]2[C:12]([O:14][CH2:15][CH3:16])=[O:13].C(=O)([O-])[O-].[K+].[K+].[CH2:23](Br)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>C(#N)C>[CH2:23]([O:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6]([CH3:11])=[C:5]2[C:12]([O:14][CH2:15][CH3:16])=[O:13])[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 820731H-Indole-3-carboxylic acid, 5-hydroxy-2-methyl-, ethyl ester

Product 1

HCID 6128625-Benzyloxy-3-ethoxycarbonyl-2-methylindoleYield 52.2%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
77.5 °C

Procedure

To a mixture of 5-hydroxy-2-methyl-1H-indole-3-carboxylic acid, ethyl ester (0.76 g, 3.47 mmol) and potassium carbonate (0.92 g, 6.67 mmol) in acetonitrile (10 ml) was added benzyl bromide (1.0 ml, 1.4 g, 8.4 mmol). The mixture was heated at 75-80° C. for 18 h. The reaction was cooled to room temperature, quenched with water, extracted with EtOAc, washed with brine, dried over Na2SO4, and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel (30% EtOAc-hexanes) to yield 5-benzyloxy-2-methyl-1H-indole-3-carboxylic acid, ethyl ester (Compound 53) as a yellow solid (0.56 g, 52%).

Workup

  1. temperatureThe reaction was cooled to room temperature
  2. customquenched with water
  3. extractionextracted with EtOAc
  4. washwashed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by flash column chromatography on silica gel (30% EtOAc-hexanes)

Sources & evidence

ORD record
ord-a58cdb672f84495b839117b4542a0592
Source dataset
uspto-grants-2010_06
Patent number
US07737173B2

Reaction notes

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