Potassium Carbonate → 4,6-Dichlorotryptophan

HRID 2379114Notes

Reaction equation

HRID 2379114 reaction equation
[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.C(=O)([O-])[O-].[K+].[K+].Br[CH2:19][C:20](=[N:26]O)[C:21]([O:23]CC)=[O:22]>C(Cl)Cl>[Cl:1][C:2]1[CH:10]=[C:9]([Cl:11])[CH:8]=[C:7]2[C:3]=1[C:4]([CH2:19][C@@H:20]([C:21]([OH:23])=[O:22])[NH2:26])=[CH:5][NH:6]2

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 144196244,6-Dichloro-1H-indoleHCID 53428735Ethyl 3-bromo-2-(hydroxyimino)propanoate

Product 1

HCID 98819644,6-DichlorotryptophanYield 99%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent3×

Procedure

Mix 4,6-dichloroindole (5.90g, 31.72mmol), potassium carbonate (1.81g, 47.6mmol) and anhydrous methylene chloride (200mL). Stir and add a solution of ethyl 3-bromo-2-hydroxyiminopropanoate (7.00g, 33.31mmol) in methylene chloride (75mL). Stir under a nitrogen atmosphere for 48 hours. Take the solution up in methylene chloride (100mL) and wash with water (300mL), saturated sodium hydrogen carbonate (200mL) and brine (100mL). Dry (MgSO4) and evaporate the solvent in vacuo to give a tan solid. Purify by silica gel chromatography (1 to 3% acetone in chloroform) to give the title compound as a yellow solid (7.00g, 99% based on consumed starting material ). Recrystallize (diethyl ether/hexane) to give the tit le compound as white crystals (4.0g, 56%); mp 175°-176° C.

Workup

  1. stirringStir under a nitrogen atmosphere for 48 hours
  2. washwash with water (300mL), saturated sodium hydrogen carbonate (200mL) and brine (100mL)
  3. dry with materialDry (MgSO4)
  4. customevaporate the solvent in vacuo
  5. customto give a tan solid
  6. customPurify by silica gel chromatography (1 to 3% acetone in chloroform)

Sources & evidence

ORD record
ord-af36cd4b4191411183a42d86fedabefb
Source dataset
uspto-grants-1994_11
Patent number
US05360814

Reaction notes

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