Acetic Anhydride → 3-Acetyl-1-benzenesulfonylindole-5-carboxylic acid methyl ester

HRID 2083865Notes

Reaction equation

HRID 2083865 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[C:5](OC(=O)C)(=[O:7])[CH3:6].[CH3:12][O:13][C:14]([C:16]1[CH:17]=[C:18]2[C:22](=[CH:23][CH:24]=1)[N:21]([S:25]([C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1)(=[O:27])=[O:26])[CH:20]=[CH:19]2)=[O:15]>ClC(Cl)C>[CH3:12][O:13][C:14]([C:16]1[CH:17]=[C:18]2[C:22](=[CH:23][CH:24]=1)[N:21]([S:25]([C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1)(=[O:26])=[O:27])[CH:20]=[C:19]2[C:5](=[O:7])[CH3:6])=[O:15]

Participants

5

Reactant 3

HCID 7918Acetic Anhydride2×HCID 6451240Aluminum(III) Chloride2×HCID 575174331H-Indole-5-carboxylic acid, 1-(phenylsulfonyl)-, methyl ester

Product 1

HCID 698902803-Acetyl-1-benzenesulfonylindole-5-carboxylic acid methyl esterYield 96%

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent2×

Procedure

To a suspension of 10.7 g (80 mmol) of aluminum chloride in dichloroethane (80 ml) was added dropwise 4.83 g (40 mmol) of acetic anhydride. After stirring for 15 min, to the mixture was added dropwise 6.31 g (20 mmol) of the above-mentioned 1-benzenesulfonylindole-5-carboxylic acid methyl ester in dichloroethane (60 ml). After stirring for 2 hours at room temperature, to the mixture were added 5.33 g (40 mmol) of aluminum chloride and 2.04 g (20 mmol) of acetic anhydride. After stirring for 30 min, the mixture was poured into ice-water, extracted with ethyl acetate. The extract was washed twice with water, aqueous sodium bicarbonate and dried, and then concentrated. The obtained crystal was washed with isopropyl ether to give 6.82 g of 3-acetyl-1-benzenesulfonylindole-5-carboxylic acid methyl ester. Yield: 96%.

Workup

  1. stirringAfter stirring for 2 hours at room temperature, to the mixture
  2. stirringAfter stirring for 30 min
  3. extractionextracted with ethyl acetate
  4. washThe extract was washed twice with water, aqueous sodium bicarbonate
  5. customdried
  6. concentrationconcentrated
  7. washThe obtained crystal was washed with isopropyl ether

Sources & evidence

ORD record
ord-3dfba29e6d2a4523a6000f7f777a830f
Source dataset
uspto-grants-2004_04
Patent number
US06716605B2

Reaction notes

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