1,4-Dibromobenzene → HCID 86700876, compound

HRID 881771Notes

Reaction equation

HRID 881771 reaction equation
[Mg].Br[C:3]1[CH:8]=[CH:7][C:6]([Br:9])=[CH:5][CH:4]=1.[CH2:10]=[C:11]1[CH2:16][CH2:15][C:14](=[O:17])[CH2:13][CH2:12]1>C1COCC1.II>[Br:9][C:6]1[CH:7]=[CH:8][C:3]([C:14]2([OH:17])[CH2:15][CH2:16][C:11](=[CH2:10])[CH2:12][CH2:13]2)=[CH:4][CH:5]=1

Participants

6

Reactant 3

HCID 78041,4-DibromobenzeneHCID 5734894-MethylenecyclohexanoneHCID 5462224Magnesium

Product 1

HCID 86700876HCID 86700876, compoundYield 36.7%

Reagents, catalysts & solvents 2

HCID 807IodineCatalystHCID 8028TetrahydrofuranSolvent3×

Procedure

To a flask charged with dry, freshly ground magnesium turnings (1.1 g, 45 mmol) and iodine (25 mg, 0.1 mmol) in THF (50 mL) was added a solution of 1,4-dibromobenzene (10.6 g, 45.0 mmol) in THF (30 mL) slowly by dropping funnel over 30 min. The resulting mixture was stirred at rt for 1 hr. The resultant grey Grignard solution was cooled to −78° C. and to it was added a solution of 4-methylenecyclohexanone (3.3 g, 30 mmol) in THF (20 mL) slowly dropwise over 20 min. The reaction was stirred at −78° C. for 30 min before being allowed to stir and warm to rt for 3 h. The resulting reaction mixture was quenched with a saturated aqueous NH4Cl solution and extracted with methyl tert-butyl ether. The combined organic phases were washed with a saturated aqueous NaCl solution, dried over MgSO4, filtered and concentrated by rotary evaporation in vacuo to afford a crude yellow oil. Purification of the crude material by column chromatography (80 g silica gel, 0-50% EtOAc:Hept, monitor for 225 nm) afforded 2.94 g of a colorless oil that was used without further purification. ESI-MS m/z: not ionized [M+H]+, retention time 1.50 min (condition E).

Workup

  1. additionTo a flask charged
  2. customwith dry
  3. customover 30 min
  4. temperatureThe resultant grey Grignard solution was cooled to −78° C. and to it
  5. stirringThe reaction was stirred at −78° C. for 30 min
  6. stirringto stir
  7. temperaturewarm to rt for 3 h
  8. customThe resulting reaction mixture
  9. customwas quenched with a saturated aqueous NH4Cl solution
  10. extractionextracted with methyl tert-butyl ether
  11. washThe combined organic phases were washed with a saturated aqueous NaCl solution
  12. dry with materialdried over MgSO4
  13. filtrationfiltered
  14. concentrationconcentrated by rotary evaporation in vacuo
  15. customto afford a crude yellow oil
  16. customPurification of the crude material by column chromatography (80 g silica gel, 0-50% EtOAc:Hept, monitor for 225 nm)

Sources & evidence

ORD record
ord-e1d785dcd0bf4346bfd4f741ec5d4dce
Source dataset
uspto-grants-2015_03
Patent number
US08993619B2

Reaction notes

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