Hydrochloric Acid → 4,6-Dichloro-1H-indole

HRID 129842Notes

Reaction equation

HRID 129842 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([Cl:11])[CH:8]=[C:7]2[C:3]=1[CH:4]=[C:5](C(O)=O)[NH:6]2.Cl>N1C2C(=CC=CC=2)C=CC=1.[Cu]>[Cl:1][C:2]1[CH:10]=[C:9]([Cl:11])[CH:8]=[C:7]2[C:3]=1[CH:4]=[CH:5][NH:6]2

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 1279884,6-Dichloro-1H-indole-2-carboxylic acid

Product 1

HCID 144196244,6-Dichloro-1H-indoleYield 93.9%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 7047QuinolineSolvent

Procedure

Dissolve 4,6-dichloro-indole-2-carboxylic acid (1.0 g, 4.35 mmol) in quinoline (25 mL). Add copper powder (100 mg) and heat to 220° C. for 3 hours. Pour the resulting black solution into cold concentrated hydrochloric acid (300 mL) and extract into ethyl ether (500 mL). Filter, wash with 1M hydrochloric acid (2×200 mL), water (100 mL) and dry (MgSO4). Evaporate the solvent in vacuo to give a brown oil (0.76 g). Purify by silica gel chromatography (17% ethyl acetate/hexane) to give the title compound as an amber oil (0.66 g, 81%).

Workup

  1. extractionextract into ethyl ether (500 mL)
  2. filtrationFilter
  3. washwash with 1M hydrochloric acid (2×200 mL), water (100 mL)
  4. dry with materialdry (MgSO4)
  5. customEvaporate the solvent in vacuo

Sources & evidence

ORD record
ord-0b8d6d74912d4f51b2c8975b0d9742ff
Source dataset
uspto-grants-1995_11
Patent number
US05470870

Reaction notes

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