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

HRID 420138

Reaction equation

HRID 420138 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.C(O[K])(C)=[O:25]>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:25])[CH3:22]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 31249Diethyl SuccinateHCID 434769981-cyclopropyl-1H-pyrrole-2-carbaldehydeHCID 178476685HCID 178476685, compound

Product 1

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

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 7918Acetic AnhydrideSolvent

Procedure

14.57 g of Na was added portionwise to 400 ml of EtOH. To the mixture was added a solution of 38.91 g of 1-cyclopropyl-1H-pyrrole-2-carbaldehyde and 48.23 ml of diethyl succinate in 100 ml of EtOH at 50° C., then the mixture was refluxed overnight. 140 ml of 5N HCl was added to the mixture at 0° C. and EtOH was evaporated. The concentrate was extracted with CHCl3 and the extract was dried over Na2SO4 and concentrated to give red oil. The material was dissolved in 400 ml of acetic anhydride and 47.40 g of AcOK 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 on SiO2 column chromatography (n-hexane-EtOAc system) to give 72.3 g of ethyl 4-acetoxy-1-cyclopropyl-1H-indole-6-carboxylate as red oil.

Workup

  1. temperaturethe mixture was refluxed overnight
  2. customEtOH was evaporated
  3. extractionThe concentrate was extracted with CHCl3
  4. dry with materialthe extract was dried over Na2SO4
  5. concentrationconcentrated
  6. customto give red oil
  7. temperatureThe mixture was refluxed for 30 min
  8. filtrationThe mixture was filtrated
  9. concentrationthe filtrate was concentrated
  10. customThe residue was purified on SiO2 column chromatography (n-hexane-EtOAc system)

Sources & evidence

ORD record
ord-a1038b9937ef49f1b3cb0b0144e10f9f
Source dataset
uspto-grants-2012_01
Patent number
US08093389B2

Linked notes

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