3,5-Difluorobenzyl bromide → Diphenylacetylene

HRID 853721Notes

Reaction equation

HRID 853721 reaction equation
F[C:2]1[CH:3]=[C:4]([CH:7]=[C:8](F)[CH:9]=1)[CH2:5]Br.[CH2:11]([Mg]Cl)[CH:12]=[CH2:13]>O1CCCC1>[C:4]1([C:5]#[C:11][C:12]2[CH:13]=[CH:8][CH:9]=[CH:2][CH:3]=2)[CH:7]=[CH:8][CH:9]=[CH:2][CH:3]=1

Participants

4

Reactant 2

HCID 5188963,5-Difluorobenzyl bromideHCID 178418473HCID 178418473, compound

Product 1

HCID 10390DiphenylacetyleneYield 177.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a dry, round bottom flask was charged 0.43 mol 3,5-difluorobenzyl-bromide and 300 ml anhydrous tetrahydrofuran. The mixture was cooled under nitrogen atmosphere to 0° C. at which time a solution of 0.54 mol allylmagnesiumchloride in 270 ml tetrahydrofuran was slowly added keeping the temperature at 0° C. After allowing to warm to room temperature and stirring until completion (20 hours), the reaction was quenched with an excess of diluted hydrochloric acid. The organic layer was separated, and the aqueous layer extracted twice with petroleum spirits (2×75 ml). The organic layers were combined, washed with water (2×75 ml) and dried over anhydrous sodium sulphate. Removal of the solvent yielded 68 g of the title compound as a pale oil.

Workup

  1. additionwas slowly added
  2. customat 0° C
  3. customthe reaction was quenched with an excess of diluted hydrochloric acid
  4. customThe organic layer was separated
  5. extractionthe aqueous layer extracted twice with petroleum spirits (2×75 ml)
  6. washwashed with water (2×75 ml)
  7. dry with materialdried over anhydrous sodium sulphate
  8. customRemoval of the solvent

Sources & evidence

ORD record
ord-cbeb486ab9ad47e3a2ec7a88e357983c
Source dataset
uspto-grants-2007_08
Patent number
US07255811B2

Reaction notes

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