Carbon Dioxide → 1,4-dimethyl-1H-indole-2-carboxylic acid

HRID 1920990Notes

Reaction equation

HRID 1920990 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[C:6]([CH3:11])[CH:7]=[CH:8][CH:9]=2)[CH:4]=[CH:3]1.[Li]CCCC.[C:17](=[O:19])=[O:18].O>CCOCC>[CH3:1][N:2]1[C:10]2[C:5](=[C:6]([CH3:11])[CH:7]=[CH:8][CH:9]=2)[CH:4]=[C:3]1[C:17]([OH:19])=[O:18]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 962WaterHCID 5893891,4-DimethylindoleHCID 178418339Butyllithium

Product 1

HCID 47777991,4-dimethyl-1H-indole-2-carboxylic acidYield 26.4%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of 1,4-dimethyl-1H-indole (0.9 g, 6.2 mmole) in anhydrous Et2O (20 mL) was treated with 2.5 M n-BuLi in hexanes (5.0 mL, 12 mmole) and the reaction was heated at reflux for 15 hr. The dark reaction mixture was poured into a slurry of excess crushed dry ice in Et2O, and the mixture was allowed to stand for 1 hr. Water (10 mL) was added, the layers separated, and the aqueous layer was filtered through Celite®. The clear filtrate was acidified with 2.0 N HCl to pH 2, and the precipitate was collected and dried to afford the title compound (0.29 g, 26.4%) as an off-white solid: MS (ES) m/e 190.2 (M+H)+.

Workup

  1. temperaturethe reaction was heated
  2. temperatureat reflux for 15 hr
  3. customThe dark reaction mixture
  4. additionwas poured into a slurry
  5. customthe layers separated
  6. filtrationthe aqueous layer was filtered through Celite®
  7. customthe precipitate was collected
  8. customdried

Sources & evidence

ORD record
ord-17ae3f64765a4d4599fcf687472b363d
Source dataset
uspto-grants-2012_05
Patent number
US08173646B2

Reaction notes

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