Quinone → 2,5-Cyclohexadien-1-one, 4-hydroxy-4-(phenylethynyl)-

HRID 623167Notes

Reaction equation

HRID 623167 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[K+].[C:11]1([C:17]#[CH:18])[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.[C:19]1(=[O:26])[CH:24]=[CH:23][C:22](=[O:25])[CH:21]=[CH:20]1>C1COCC1>[OH:25][C:22]1([C:18]#[C:17][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH:23]=[CH:24][C:19](=[O:26])[CH:20]=[CH:21]1

Participants

5

Reactant 3

HCID 4650QuinoneHCID 10821PhenylacetyleneHCID 3251421Potassium bis(trimethylsilyl)amide

Product 1

HCID 110091862,5-Cyclohexadien-1-one, 4-hydroxy-4-(phenylethynyl)-

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

A suspension of potassium bis(trimethylsilyl)amide (1.95 g, 0.0098 mole) in 20 mL of dry THF was treated with phenylacetylene (0.92 g, 0.009 mole). A flocculant white precipitate formed immediately. Benzoquinone (0.97 g, 0.009 mole) was dissolved in dry THF (10 mL) and cooled to -78° C. The potassium phenylacetylide generated above was added dropwise over a period of about 10 min. The reaction was stirred an additional 10 min, quenched by adding saturated ammonium chloride solution (20 mL) and allowed to warm to RT. The mixture was diluted with saturated ammonium chloride solution, extracted with ether and filtered to remove a flocculant dark brown precipitate. The phases were separated and the aqueous phase extracted with additional ether. The combined ether extracts were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flask chromatography on silica gel using 4:1 hexane/EtOAc as the eluent and the fractions containing the title product were combined and concentrated in vacuo to yield 0.27 g (14%).

Workup

  1. customA flocculant white precipitate formed immediately
  2. additionabove was added dropwise over a period of about 10 min
  3. customquenched
  4. additionby adding saturated ammonium chloride solution (20 mL)
  5. temperatureto warm to RT
  6. additionThe mixture was diluted with saturated ammonium chloride solution
  7. extractionextracted with ether
  8. filtrationfiltered
  9. customto remove a flocculant dark brown precipitate
  10. customThe phases were separated
  11. extractionthe aqueous phase extracted with additional ether
  12. dry with materialThe combined ether extracts were dried over anhydrous sodium sulfate
  13. filtrationfiltered
  14. concentrationconcentrated in vacuo
  15. customThe residue was purified by flask chromatography on silica gel using 4:1 hexane/EtOAc as the eluent
  16. additionthe fractions containing the title product
  17. concentrationconcentrated in vacuo
  18. customto yield 0.27 g (14%)

Sources & evidence

ORD record
ord-1322c14bcebb4bf59906f0297a1d4365
Source dataset
uspto-grants-1988_09
Patent number
US04772755

Reaction notes

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