Dimethyl Sulfoxide → ethyl 2-methyl-1H-indole-3-carboxylate

HRID 2206538Notes

Reaction equation

HRID 2206538 reaction equation
CS(C)=O.I[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[NH2:12].O=[C:14]([CH3:21])[CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17].C(=O)([O-])[O-].[Cs+].[Cs+]>[Cu-]=O.O>[CH3:21][C:14]1[NH:12][C:7]2[C:6]([C:15]=1[C:16]([O:18][CH2:19][CH3:20])=[O:17])=[CH:11][CH:10]=[CH:9][CH:8]=2

Participants

7

Reactant 4

HCID 679Dimethyl SulfoxideHCID 8868Ethyl AcetoacetateHCID 10796Cesium carbonateHCID 119952-Iodoaniline

Product 1

HCID 4072358ethyl 2-methyl-1H-indole-3-carboxylateYield 57.5%

Reagents, catalysts & solvents 2

HCID 178419072HCID 178419072, compoundCatalystHCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

To a mixed solution of dimethyl sulfoxide (100 mL) and water (34 mL), 2-iodobenzenamine (50 g, 228 mmol), ethyl 3-oxobutanoate (35.6 g, 274 mmol), copper(I) oxide (3.3 g, 22.8 mmol) and cesium carbonate (75 g, 228 mmol) was added. The mixture was stirred at 100° C. for 16 hours under nitrogen gas atmosphere. The reaction mixture was filtered through a pad of celite. The filtrate was diluted with water and extracted with ethyl acetate. The organic phase was concentrated in vacuo, and then the residue was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=5:1) to afford the title compound as a light yellow solid (26.6 g, 57.5%). LCMS 204 (M+H)+.

Workup

  1. filtrationThe reaction mixture was filtered through a pad of celite
  2. additionThe filtrate was diluted with water
  3. extractionextracted with ethyl acetate
  4. concentrationThe organic phase was concentrated in vacuo
  5. customthe residue was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=5:1)

Sources & evidence

ORD record
ord-988dbae24dcc4bf4a13c656d1788e1a0
Source dataset
uspto-grants-2016_06
Patent number
US09371331B2

Reaction notes

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