1,3-Diphenyl-2-propanone → 6,6-Dibenzylfulvene

HRID 746976Notes

Reaction equation

HRID 746976 reaction equation
[CH:1]1[CH2:5][CH:4]=[CH:3][CH:2]=1.C([Li])CCC.[CH2:11]([C:18]([CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)=O)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.[Cl-].[NH4+]>O1CCCC1.CCOCC.CCCCCC>[CH2:20]([C:18]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[C:2]1[CH:1]=[CH:5][CH:4]=[CH:3]1)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

8

Reactant 4

HCID 75931,3-Diphenyl-2-propanoneHCID 7612CyclopentadieneHCID 25517Ammonium ChlorideHCID 178418339Butyllithium

Product 1

HCID 187875436,6-Dibenzylfulvene

Reagents, catalysts & solvents 3

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

Into a 100 ml Kjeldahl flask purged thoroughly with nitrogen, equipped with a dropping funnel and a magnetic stirrer, were introduced cyclopentadiene 2.40 g (36.2 mmol) which had been subjected to cracking, and dehydrated tetrahydrofuran 50 ml. With cooling in an ice bath, 1.57 mol/L n-hexane solution of n-butyllithium, 24.3 ml (38.1 mmol), was dropwise added to the solution by means of the dropping funnel. The resulting slurry was stirred all night at room temperature. With the flask cooled in an ice bath, a solution of dibenzyl ketone 9.16 g (43.6 mmol) in 20 ml of dehydrated tetrahydrofuran, was dropwise added into the flask by means of the dropping funnel. The resulting slurry was stirred all night at room temperature. After addition of a saturated aqueous solution of ammonium chloride 50 ml and ether 50 ml, the organic phase was recovered with a separatory funnel. The water phase was extracted with ether 30 ml. The organic phase was washed twice with water 50 ml and once with a saturated salt solution 50 ml, and dried over magnesium sulfate. The solution was filtered to remove the magnesium sulfate, and the solvent of the filtrate was distilled away to obtain a solid. The residue was subjected to column chromatography to obtain an objective brown oil in 1.10 g (12%) yield. The 1H NMR spectrum and the FD-MS spectrum as measured with respect to the brown oil are given below:

Workup

  1. customInto a 100 ml Kjeldahl flask purged thoroughly with nitrogen
  2. customequipped with a dropping funnel and a magnetic stirrer
  3. temperatureWith cooling in an ice bath
  4. temperatureWith the flask cooled in an ice bath
  5. stirringThe resulting slurry was stirred all night at room temperature
  6. customthe organic phase was recovered with a separatory funnel
  7. extractionThe water phase was extracted with ether 30 ml
  8. washThe organic phase was washed twice with water 50 ml and once with a saturated salt solution 50 ml
  9. dry with materialdried over magnesium sulfate
  10. filtrationThe solution was filtered
  11. customto remove the magnesium sulfate
  12. distillationthe solvent of the filtrate was distilled away
  13. customto obtain a solid
  14. customto obtain an objective brown oil in 1.10 g (12%)
  15. customyield

Sources & evidence

ORD record
ord-6024f38cf0ca4c328105f05f3c29ce35
Source dataset
uspto-grants-2008_07
Patent number
US07393965B2

Reaction notes

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