Cyclopentadiene → 5-Fluoro-1,4-dihydro-1,4-methanonaphthalene

HRID 857033Notes

Reaction equation

HRID 857033 reaction equation
F[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1I.[CH:10]1[CH2:14][CH:13]=[CH:12][CH:11]=1.[Li]CCCC>CCOCC>[F:8][C:4]1[CH:5]=[CH:6][CH:7]=[C:2]2[C:3]=1[CH:14]1[CH2:13][CH:12]2[CH:11]=[CH:10]1

Participants

5

Reactant 3

HCID 7612CyclopentadieneHCID 27827381,3-Difluoro-2-iodobenzeneHCID 178418339Butyllithium

Product 1

HCID 1437965-Fluoro-1,4-dihydro-1,4-methanonaphthalene

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

A solution of 2,6-difluoroiodobenzene (5.0 g, 20.8 mmol) and cyclopentadiene (2.07 g, 31.3 mmol) was stirred at 0° C. in P. ether (70 mL, 40–60° C.) under N2 and treated with n-BuLi (8.74 mL, 2.5M in hexanes, 21.8 mmol) dropwise over 10 minutes. The reaction was quenched after 15 minutes by addition of aqueous 1N HCl solution and the product was extracted with hexanes (3×50 mL). The combined organic layer was washed with H2O (50 mL), saturated aqueous NaCl solution (50 mL), dried (MgSO4), filtered and evaporated. Chromatography on Silica gel provided product as an oil (1.5 g, 45%). (TLC hexanes Rf 0.55). 1H NMR (400 MHz, CDCl3) δ 7.08 (ddd, J=7.0,1.0,0.8 Hz, 1H), 6.96 (ddd, J=8.5, 8.3, 7.0 Hz, 1H), 6.86 (br s, 2H), 6.72 (ddd, J=8.5,8.3,0.8 Hz, 1H), 4.25 (br s, 1H), 3.98 (br s, 1H), 2.36 (ddd, J=7.2, 1.7, 1.7 Hz, 1H), 2.30 (ddd, J=7.2, 1.7, 1.5 Hz, 1H). GCMS m/e 160 (M+).

Workup

  1. customThe reaction was quenched after 15 minutes by addition of aqueous 1N HCl solution
  2. extractionthe product was extracted with hexanes (3×50 mL)
  3. washThe combined organic layer was washed with H2O (50 mL), saturated aqueous NaCl solution (50 mL)
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. customevaporated

Sources & evidence

ORD record
ord-02212d8421b44a7d86e3702d65669b1e
Source dataset
uspto-grants-2006_12
Patent number
US07144882B2

Reaction notes

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