Cyclopentadiene → 6-Fluoro-1,4-dihydro-1,4-methanonaphthalene

HRID 857031Notes

Reaction equation

HRID 857031 reaction equation
[Mg].[CH:2]1[CH2:6][CH:5]=[CH:4][CH:3]=1.F[C:8]1[CH:13]=[CH:12][C:11]([F:14])=[CH:10][C:9]=1Br>C1COCC1>[F:14][C:11]1[CH:10]=[C:9]2[C:8](=[CH:13][CH:12]=1)[CH:4]1[CH2:5][CH:6]2[CH:2]=[CH:3]1

Participants

5

Reactant 3

HCID 7612CyclopentadieneHCID 678622-Bromo-1,4-difluorobenzeneHCID 5462224Magnesium

Product 1

HCID 1435636-Fluoro-1,4-dihydro-1,4-methanonaphthalene

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Magnesium turnings (0.66 g, 27.2 mmol) were stirred in anhydrous THF (10 mL) in a flame dried 75 mL 3 neck round bottom flask equipped with a non-equalizing addition funnel with a N2 flow adapter, magnetic stirrer and efficient condenser equipped with a N2 flow adapter. The flask was stirred and warmed to reflux by a removable heating mantle. 2,5-Difluorobromobenzene (0.1 g) was added followed by of 3N EtMgBr in THF (0.1 mL). The addition funnel was charged with an intimate mixture of cyclopentadiene (1.71 g, 25.9 mmol) and 2,5-difluorobromobenzene (5.0 g, 25.9 mmol). Small portions (0.2 mL) of the intimate mixture were introduced to assist initiation (˜4 times). After ˜15 minutes, the reaction initiated (exotherm, and vapor condensation) and heating was maintained as necessary during the addition of the contents of the addition funnel. The reaction was then maintained at reflux for 1 hour.

Workup

  1. dry with materialdried 75 mL 3 neck round bottom flask
  2. customequipped with a non-equalizing addition funnel with a N2 flow adapter, magnetic stirrer and efficient condenser
  3. customequipped with a N2 flow adapter
  4. temperaturewarmed
  5. temperatureto reflux by a removable heating mantle
  6. addition2,5-Difluorobromobenzene (0.1 g) was added
  7. custom(exotherm, and vapor condensation)
  8. temperatureheating
  9. temperaturewas maintained as
  10. additionnecessary during the addition of the contents of the addition funnel
  11. temperatureThe reaction was then maintained
  12. temperatureat reflux for 1 hour

Sources & evidence

ORD record
ord-8b9d3a8237a84f93aa05a57c8d244521
Source dataset
uspto-grants-2006_12
Patent number
US07144882B2

Reaction notes

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