Hydrochloric Acid → ethyl 3-phenyl-1H-indole-2-carboxylate

HRID 430642Notes

Reaction equation

HRID 430642 reaction equation
O=[C:2]([CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[C:3]([O:5][CH2:6][CH3:7])=[O:4].[C:15]1([NH:21]N)[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.C(O)C.Cl>S(=O)(=O)(O)O.O>[C:9]1([C:8]2[C:20]3[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=3)[NH:21][C:2]=2[C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 702EthanolHCID 7516PhenylhydrazineHCID 12292599Ethyl 2-oxo-3-phenylpropanoate

Product 1

HCID 2763656ethyl 3-phenyl-1H-indole-2-carboxylateYield 32%

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 962WaterSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of Example 1A (7.81 g, 40.7 mmol) and phenylhydrazine (4.00 mL, 40.7 mmol) was treated with concentrated sulfuric acid (4 drops), heated to 120° C. for 15 minutes, cooled to room temperature, treated with ethanol (50 mL), treated with bubbling HCl gas for 2 minutes, and heated to reflux for 1 hour. The mixture was poured into water (100 mL) and extracted with diethyl ether. The combined extracts were washed with water and brine, dried (Na2SO4), filtered, and concentrated. The concentrate was recrystallized from ethanol to provide 3.43 g (32%) of the desired product.

Workup

  1. temperaturecooled to room temperature
  2. temperatureheated
  3. temperatureto reflux for 1 hour
  4. extractionextracted with diethyl ether
  5. washThe combined extracts were washed with water and brine
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe concentrate was recrystallized from ethanol

Sources & evidence

ORD record
ord-613d76dc90294ec19f3248afa1b00928
Source dataset
uspto-grants-2001_11
Patent number
US06323228B1

Reaction notes

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