Hydrochloric Acid → Thiazole, 2,5-di-2-thienyl-

HRID 2352582Notes

Reaction equation

HRID 2352582 reaction equation
Br[C:2]1[S:3][C:4](Br)=[CH:5][N:6]=1.[S:8]1[CH:12]=[CH:11][CH:10]=[C:9]1[Mg]Br.Cl>Cl[Ni]1(Cl)[P](C2C=CC=CC=2)(C2C=CC=CC=2)CCC[P]1(C1C=CC=CC=1)C1C=CC=CC=1.CCOCC>[S:8]1[CH:12]=[CH:11][CH:10]=[C:9]1[C:2]1[S:3][C:4]([C:9]2[S:8][CH:12]=[CH:11][CH:10]=2)=[CH:5][N:6]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 3123942,5-DibromothiazoleHCID 178418438HCID 178418438, compound

Product 1

HCID 185782Thiazole, 2,5-di-2-thienyl-Yield 5.8%

Reagents, catalysts & solvents 2

HCID 178418745HCID 178418745, compoundCatalystHCID 3283Diethyl EtherSolvent

Procedure

When a three-neck 50-ml flask fitted with a reflux condenser, a stirrer, and a calcium chloride tube was charged with 6.45 g (40 m.mols) of 2-bromothiophene and 29 ml of dehydrated ether and then 1.06 g (44 m.mols) of a magnesium metal was added thereto, the resultant reaction mixture produced 2-thienyl magnesium bromide with evolution of heat. Under an atmosphere of nitrogen, 4.0 g (16 m.mols) of 2,5-dibromothiazole, 0.179 g (0.33 m.mol) of dichloro[1,3-bis(diphenylphosphino)propane]nickel, and 29 ml of dehydrated ether were added to the 2-thienyl magnesium bromide. The resultant mixture was placed and refluxed for 16 hours in a three-necked 100-ml flask fitted with a reflux condenser, a stirrer, and a calcium chloride tube. The reaction mixture was treated with 1N hydrochloric acid and the water layer separated from the organic layer was extracted with ether. The organic layer was added to the water layer extracted with ether. The resultant liquid was washed with water, cleaned with a saturated aqueous sodium hydrogen carbonate solution, and then washed again with water. The washed liquid layer was dried with anhydrous sodium sulfate, treated with activated carbon, and recrystallized twice with n-hexane, to produce 237 mg (5.8%) of yellow leaflike crystals of 2,5-di(2-thienyl)thiazole having a melting point of 93.0° to 93.8° C.

Workup

  1. temperatureof heat
  2. temperaturerefluxed for 16 hours in a three-necked 100-ml flask
  3. customfitted with a reflux condenser, a stirrer, and a calcium chloride tube
  4. customthe water layer separated from the organic layer
  5. extractionwas extracted with ether
  6. additionThe organic layer was added to the water layer
  7. extractionextracted with ether
  8. washThe resultant liquid was washed with water
  9. washwashed again with water
  10. dry with materialThe washed liquid layer was dried with anhydrous sodium sulfate
  11. additiontreated with activated carbon
  12. customrecrystallized twice with n-hexane

Sources & evidence

ORD record
ord-2a394f8600764e6a983fe9b8dc402a98
Source dataset
uspto-grants-1989_10
Patent number
US04877852

Reaction notes

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