Sodium Carbonate → 5-Chloro-2,2'-bithiophene

HRID 1625785Notes

Reaction equation

HRID 1625785 reaction equation
Br[C:2]1[S:3][C:4]([Cl:7])=[CH:5][CH:6]=1.[S:8]1[CH:12]=[CH:11][CH:10]=[C:9]1B(O)O.C(=O)([O-])[O-].[Na+].[Na+]>C(COC)OC.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[Cl:7][C:4]1[S:3][C:2]([C:9]2[S:8][CH:12]=[CH:11][CH:10]=2)=[CH:6][CH:5]=1

Participants

6

Reactant 3

HCID 10340Sodium CarbonateHCID 761332-Bromo-5-chlorothiopheneHCID 27339602-Thiopheneboronic acid

Product 1

HCID 125014505-Chloro-2,2'-bithiopheneYield 80.7%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 80711,2-DimethoxyethaneSolvent

Procedure

To a solution of 2-bromo-5-chlorothiophene (4.11 g), thiophene-2-boronic acid (4.00 g), tetrakis(triphenylphosphine)palladium (0) (1.20 g) and 2M aqueous sodium carbonate solution (31.3 ml) in dimethoxyethane (100 ml) was heated under reflux under argon atmosphere for 2.5 hours. The reaction mixture was cooled, and extracted with ethyl acetate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane) to give 2-(5-chloro-2-thienyl)thiophene (3.37 g) as pale yellow oil.

Workup

  1. temperatureunder reflux under argon atmosphere for 2.5 hours
  2. temperatureThe reaction mixture was cooled
  3. extractionextracted with ethyl acetate
  4. customThe solvent was evaporated under reduced pressure
  5. customthe residue was purified by silica gel column chromatography (hexane)

Sources & evidence

ORD record
ord-b71ab5907cef452a995f752776fabae0
Source dataset
uspto-grants-2014_07
Patent number
US08785403B2

Reaction notes

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