Sulfuric Acid → 1H,2H,3H,4H-cyclopenta(b)indole-5-carboxylic acid

HRID 916609

Reaction equation

HRID 916609 reaction equation
Cl.[NH:2]([C:4]1[CH:12]=[CH:11][CH:10]=[CH:9][C:5]=1[C:6]([OH:8])=[O:7])N.[C:13]1(=O)[CH2:17][CH2:16][CH2:15][CH2:14]1.OS(O)(=O)=O>O1CCOCC1>[CH2:15]1[C:14]2[C:12]3[C:4](=[C:5]([C:6]([OH:8])=[O:7])[CH:9]=[CH:10][CH:11]=3)[NH:2][C:13]=2[CH2:17][CH2:16]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 8452CyclopentanoneHCID 104169Benzoic acid, 2-hydrazinyl-, hydrochloride (1:1)

Product 1

HCID 121329741H,2H,3H,4H-cyclopenta(b)indole-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a stirred solution of 2-hydrazinobenzoic acid hydrochloride (53 mmol, 10.0 g) and cyclopentanone (58 mmol, 4.9 g) in 1,4-dioxane (100 mL) was added dropwise concentrated H2SO4 (˜18M, 63 mmol, 3.5 mL). The resulting solution was heated to reflux for 2 hours. 1H NMR analysis of a crude aliquot indicated complete reaction. The reaction was allowed to cool to room temperature and then concentrated to dryness to give a red solid which was used without further purification.

Workup

  1. temperatureThe resulting solution was heated
  2. temperatureto reflux for 2 hours
  3. custom1H NMR analysis of a crude aliquot indicated complete reaction
  4. concentrationconcentrated to dryness
  5. customto give a red solid which
  6. customwas used without further purification

Sources & evidence

ORD record
ord-d19e979f80864369988b07cb138fccf9
Source dataset
uspto-grants-2007_09
Patent number
US07271163B2

Linked notes

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