Lawesson's reagent → 2-(3-Bromo-phenyl)-5-methyl-thiophene

HRID 551123Notes

Reaction equation

HRID 551123 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:8](=O)[CH2:9][CH2:10][C:11](=O)[CH3:12])[CH:5]=[CH:6][CH:7]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:24])=CC=1>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[S:24][C:11]([CH3:12])=[CH:10][CH:9]=2)[CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 87949Lawesson's reagentHCID 393572221-(3-Bromo-phenyl)-pentane-1,4-dione

Product 1

HCID 598296762-(3-Bromo-phenyl)-5-methyl-thiopheneYield 66.4%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a stirring solution of 1-(3-bromo-phenyl)-pentane-1,4-dione (18.32 mmol) in toluene (90 mL) was added Lawesson's Reagent (19.24 mmol, 1.05 eq.) and the mixture was heated to reflux for 20 min. The reaction mixture was then cooled to room temperature and diluted with 1:1 hexanes/ether (90 mL) resulting in a precipitate. The mixture was filtered through a small pad of celite and the filtrate was concentrated to a light yellow solid that was purified by recrystallization from hexanes to give the final product as a white solid (12.17 mmol, 66%). MS (ESI) m/z 254.3.

Workup

  1. temperaturethe mixture was heated
  2. temperatureto reflux for 20 min
  3. customresulting in a precipitate
  4. filtrationThe mixture was filtered through a small pad of celite
  5. concentrationthe filtrate was concentrated to a light yellow solid
  6. customthat was purified by recrystallization from hexanes

Sources & evidence

ORD record
ord-d53184b5b0444919af315872bf7cbf4a
Source dataset
uspto-grants-2011_05
Patent number
US07947712B2

Reaction notes

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