2-(ethoxycarbonyl)-1-tosyl-1H-indole-5-carboxylic acid → 1-(toluene-4-sulfonyl)-1H-indole-2,5-dicarboxylic acid 5-tert-butyl ester 2-ethyl ester

HRID 513843Notes

Reaction equation

HRID 513843 reaction equation
[CH3:1][CH2:2][O:3][C:4]([C:6]1[N:7]([S:18]([C:21]2[CH:26]=[CH:25][C:24]([CH3:27])=[CH:23][CH:22]=2)(=[O:20])=[O:19])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([OH:17])=[O:16])=[CH:10][CH:9]=2)=[O:5]>C(OC(OC(C)(C)C)N(C)C)(C)(C)C.C(OCC)(=O)C.O>[CH3:1][CH2:2][O:3][C:4]([C:6]1[N:7]([S:18]([C:21]2[CH:22]=[CH:23][C:24]([CH3:27])=[CH:25][CH:26]=2)(=[O:20])=[O:19])[C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([O:17][C:11]([CH3:15])([CH3:12])[CH3:10])=[O:16])=[CH:10][CH:9]=2)=[O:5]

Participants

5

Reactant 1

HCID 680048532-(ethoxycarbonyl)-1-tosyl-1H-indole-5-carboxylic acid

Product 1

HCID 680053211-(toluene-4-sulfonyl)-1H-indole-2,5-dicarboxylic acid 5-tert-butyl ester 2-ethyl esterYield 134.3%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 5477121,1-bis(1,1-dimethylethoxy)-N,N,N-trimethylamineSolvent2×

Conditions

Temperature
80 °C

Procedure

1-(Toluene-4-sulfonyl)-1H-indole-2,5-dicarboxylic acid 2-ethyl ester (690 mg, 1.85 mmol) was dissolved in N,N-dimethylformamide di-tert-butyl acetal (3.0 ml), and stirred at 80° C. for two and half hours. N,N-dimethylformamide di-tert-butyl acetal (2.0 ml) was further added thereto and stirred at 80° C. for three hours. After cooling to room temperature, the reaction mixture was diluted with ethyl acetate (150 ml) and water (75 ml). The organic layer was isolated, washed with water and a saturated aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate. The desiccant was removed by filtration. The filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=25/1 to 5/1) to give 1-(toluene-4-sulfonyl)-1H-indole-2,5-dicarboxylic acid 5-tert-butyl ester 2-ethyl ester (551 mg, 69%).

Workup

  1. stirringstirred at 80° C. for three hours
  2. temperatureAfter cooling to room temperature
  3. customThe organic layer was isolated
  4. washwashed with water
  5. dry with materiala saturated aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate
  6. customThe desiccant was removed by filtration
  7. concentrationThe filtrate was concentrated under reduced pressure
  8. customThe resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=25/1 to 5/1)

Sources & evidence

ORD record
ord-20ac465b05dd4ef1abd6573c41676e90
Source dataset
uspto-grants-2015_08
Patent number
US09102692B2

Reaction notes

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