Lawesson's reagent → 6,7-Dichloro-2,3-dimethoxy-5-thioacetamidoquinoxaline

HRID 842676Notes

Reaction equation

HRID 842676 reaction equation
[C:1]([NH:4][C:5]1[C:14]([Cl:15])=[C:13]([Cl:16])[CH:12]=[C:11]2[C:6]=1[N:7]=[C:8]([O:19][CH3:20])[C:9]([O:17][CH3:18])=[N:10]2)(=O)[CH3:2].COC1C=CC(P2(=S)SP(=S)(C3C=CC(OC)=CC=3)[S:30]2)=CC=1>C1(C)C=CC=CC=1>[Cl:15][C:14]1[C:5]([NH:4][C:1](=[S:30])[CH3:2])=[C:6]2[C:11](=[CH:12][C:13]=1[Cl:16])[N:10]=[C:9]([O:17][CH3:18])[C:8]([O:19][CH3:20])=[N:7]2

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 22614897HCID 22614897, compound

Product 1

HCID 226148756,7-Dichloro-2,3-dimethoxy-5-thioacetamidoquinoxalineYield 135.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

5-Acetamido-6,7-dichloro-2,3-dimethoxyquinoxaline (20.49 g, 64.8 mmol) was added to a stirred suspension of 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide (Lawesson's reagent) (15.7 g, 38.9 mmol) in toluene (432 ml) at room temperature under nitrogen. The mixture was warmed to the reflux temperature 25 minutes and was maintained at that temperature for a further 90 minutes. After being cooled the mixture was concentrated under reduced pressure and the residue purified by flash chromatography on silica gel, eluting with dichloromethane. 6,7-Dichloro-2,3-dimethoxy-5-thioacetamidoquinoxaline (17.54 g, 81%) was obtained as a yellow foam.

Workup

  1. temperatureThe mixture was warmed to the reflux temperature 25 minutes
  2. temperaturewas maintained at that temperature for a further 90 minutes
  3. temperatureAfter being cooled the mixture
  4. concentrationwas concentrated under reduced pressure
  5. customthe residue purified by flash chromatography on silica gel
  6. washeluting with dichloromethane

Sources & evidence

ORD record
ord-654b969f0a0d4737966e464ba3df1b6d
Source dataset
uspto-grants-2002_04
Patent number
US06376490B1

Reaction notes

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