Citric Acid → 7-[ethyl(2-thienylsulfonyl)amino]-4-methyl-1H-indole-2-carboxylic acid

HRID 1994713Notes

Reaction equation

HRID 1994713 reaction equation
[CH2:1]([N:3]([S:19]([C:22]1[S:23][CH:24]=[CH:25][CH:26]=1)(=[O:21])=[O:20])[C:4]1[CH:5]=[CH:6][C:7]([CH3:18])=[C:8]2[C:12]=1[NH:11][C:10]([C:13]([O:15]CC)=[O:14])=[CH:9]2)[CH3:2].CO.[OH-].[K+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[CH2:1]([N:3]([S:19]([C:22]1[S:23][CH:24]=[CH:25][CH:26]=1)(=[O:20])=[O:21])[C:4]1[CH:5]=[CH:6][C:7]([CH3:18])=[C:8]2[C:12]=1[NH:11][C:10]([C:13]([OH:15])=[O:14])=[CH:9]2)[CH3:2]

Participants

6

Reactant 4

HCID 311Citric AcidHCID 887MethanolHCID 14797Potassium HydroxideHCID 57476012ethyl 7-[ethyl(2-thienylsulfonyl)amino]-4-methyl-1H-indole-2-carboxylate

Product 1

HCID 574760137-[ethyl(2-thienylsulfonyl)amino]-4-methyl-1H-indole-2-carboxylic acidYield 101.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 7-[ethyl(2-thienylsulfonyl)amino]-4-methyl-1H-indole-2-carboxylate (2.12 g) in tetrahydrofuran (15 ml)-methanol (15 ml) was added an aqueous solution (5 ml) of 85% potassium hydroxide (1.0 g), and the mixture was stirred at room temperature for 15 hr. The reaction solution was acidified with aqueous citric acid solution, and extracted with ethyl acetate. The extract was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give 7-[ethyl(2-thienylsulfonyl)amino]-4-methyl-1H-indole-2-carboxylic acid (2.0 g, yield quantitative) as a colorless amorphous solid. To a mixture of the obtained solid (2.0 g), 1H-1,2,3-benzotriazol-1-ol-ammonia complex (1.0 g) and N,N-dimethylformamide (20 ml) was added N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride (1.3 g) under ice-cooling, and the mixture was stirred at room temperature for 2 days. The reaction solution was diluted with ethyl acetate, and washed successively with aqueous sodium hydrogencarbonate solution, water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was subjected to silica gel column chromatography (ethyl acetate:hexane=1:1-3:1) to give the title compound (2.0 g, yield quantitative) as a colorless amorphous solid.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe extract was washed with water and saturated brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-da0ead81f9d44eb3a4b7948b6e8683c4
Source dataset
uspto-grants-2010_01
Patent number
US07652133B2

Reaction notes

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