Hydrochloric Acid → ethyl 4-acetoxy-1-cyclopropyl-1H-indole-6-carboxylate

HRID 38490

Reaction equation

HRID 38490 reaction equation
[CH:1]1([N:4]2[CH:8]=[CH:7][CH:6]=[C:5]2[CH:9]=O)[CH2:3][CH2:2]1.[C:11]([O:20][CH2:21][CH3:22])(=O)[CH2:12][CH2:13][C:14]([O:16][CH2:17][CH3:18])=[O:15].Cl.CC([O-])=[O:26].[K+]>CCO.C(OC(=O)C)(=O)C>[C:21]([O:20][C:11]1[CH:12]=[C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:9]=[C:5]2[C:6]=1[CH:7]=[CH:8][N:4]2[CH:1]1[CH2:2][CH2:3]1)(=[O:26])[CH3:22]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 31249Diethyl SuccinateHCID 517044Potassium AcetateHCID 434769981-cyclopropyl-1H-pyrrole-2-carbaldehyde

Product 1

HCID 57930960ethyl 4-acetoxy-1-cyclopropyl-1H-indole-6-carboxylate

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 7918Acetic AnhydrideSolvent

Procedure

Na (14.6 g) was added portion wise to EtOH (400 ml) with stirring at room temperature. To the mixture was added a solution of 1-cyclopropyl-1H-pyrrole-2-carbaldehyde (38.9 g) and diethyl succinate (48.2 ml) in EtOH (100 ml) at 50° C., then the mixture was refluxed overnight. 140 ml of aqueous 5N HCl was added to the mixture at 0° C. and EtOH was evaporated. The residue was extracted with CHCl3, the organic layer was dried over Na2SO4 and concentrated to give red oil. The material was dissolved in 400 ml of acetic anhydride and KOAc (47.4 g) was added thereto. The mixture was refluxed for 30 min. and allowed to cool to room temperature. The mixture was filtrated and the filtrate was concentrated. The residue was purified by silicagel column chromatography (hexane/EtOAc) to give intended compound a red oil.

Workup

  1. temperaturethe mixture was refluxed overnight
  2. customEtOH was evaporated
  3. extractionThe residue was extracted with CHCl3
  4. dry with materialthe organic layer was dried over Na2SO4
  5. concentrationconcentrated
  6. customto give red oil
  7. temperatureThe mixture was refluxed for 30 min.
  8. temperatureto cool to room temperature
  9. filtrationThe mixture was filtrated
  10. concentrationthe filtrate was concentrated
  11. customThe residue was purified by silicagel column chromatography (hexane/EtOAc)
  12. customto give

Sources & evidence

ORD record
ord-0f616e70cc5c40efbc4a893598adad59
Source dataset
uspto-grants-2013_09
Patent number
US08524730B2

Linked notes

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