p-Toluenesulfonic acid → (E)-5-[3-(4-fluorophenyl)-1-isopropyl-1H-indol-2-yl]-3-oxopent-4-enoic acid methyl ester

HRID 352095Notes

Reaction equation

HRID 352095 reaction equation
[CH3:1][O:2][C:3](=[O:29])[CH:4]=[C:5]([OH:28])[CH2:6][CH:7]([C:9]1[N:10]([CH:25]([CH3:27])[CH3:26])[C:11]2[C:16]([C:17]=1[C:18]1[CH:23]=[CH:22][C:21]([F:24])=[CH:20][CH:19]=1)=[CH:15][CH:14]=[CH:13][CH:12]=2)O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3](=[O:29])[CH2:4][C:5](=[O:28])/[CH:6]=[CH:7]/[C:9]1[N:10]([CH:25]([CH3:26])[CH3:27])[C:11]2[C:16]([C:17]=1[C:18]1[CH:19]=[CH:20][C:21]([F:24])=[CH:22][CH:23]=1)=[CH:15][CH:14]=[CH:13][CH:12]=2

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 698910965-[3-(4-Fluorophenyl)-1-isopropyl-1H-indol-2-yl]-3,5-dihydroxypent-2-enoic Acid Methyl Ester

Product 1

HCID 11326444(E)-5-[3-(4-fluorophenyl)-1-isopropyl-1H-indol-2-yl]-3-oxopent-4-enoic acid methyl ester

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

1 g of crude 5-[3-(4-fluorophenyl)-1-isopropyl-1H-indol-2-yl]-3,5-dihydroxypent-2-enoic acid methyl ester in 50 ml of toluene are introduced into a 100 ml three-necked round-bottomed flask equipped with a magnetic stirrer, thermometer, reflux condenser and nitrogen delivery line, 48 mg (0.025 mmol) of toluene-4-sulfonic acid are added and the mixture is stirred for 4 hours under reflux. The mixture is then cooled to room temperature, washed once with 25 ml of saturated sodium hydrogen carbonate solution and twice with 50 ml of saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated by evaporation. The crude product is purified by means of flash chromatography (hexane/ethyl acetate=9:1). An orange resin is obtained which, according to NMR, is the product in a keto-enol equilibrium of approximately 3:1.

Workup

  1. customequipped with a magnetic stirrer
  2. temperaturethermometer, reflux condenser
  3. temperatureunder reflux
  4. washwashed once with 25 ml of saturated sodium hydrogen carbonate solution and twice with 50 ml of saturated sodium chloride solution
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated by evaporation
  8. customThe crude product is purified by means of flash chromatography (hexane/ethyl acetate=9:1)
  9. customAn orange resin is obtained which

Sources & evidence

ORD record
ord-3cb07c56fc29493fab48a62fa48fd9d1
Source dataset
uspto-grants-2004_06
Patent number
US06743926B2

Reaction notes

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