Ammonia → 4,4-Diphenyl-1-butene

HRID 275470Notes

Reaction equation

HRID 275470 reaction equation
N.[Li].[C:3]1([C:9]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)(OC)[CH2:10][CH:11]=[CH2:12])[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.C=CC(=C)C>C1COCC1.C(Cl)(Cl)Cl>[C:3]1([CH:9]([C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)[CH2:10][CH:11]=[CH2:12])[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1

Participants

7

Reactant 4

HCID 222AmmoniaHCID 6557IsopreneHCID 3028194Lithium2×HCID 12235654Benzene, 1,1'-(1-methoxy-3-butenylidene)bis-

Product 1

HCID 118306504,4-Diphenyl-1-buteneYield 102.6%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

Ammonia, 400 mL, was cooled to -78° C. and 1.15 g of lithium wire was added. After the lithium had dissolved, a solution of 15.5 g of 4,4-diphenyl-4-methoxybut-1-ene in 100 mL of THF was added dropwise, over 1 hr. The mixture was warmed to reflux, then cooled to -78° C. Isoprene, 4 mL, was added to the reaction mixture to quench excess lithium, followed by 4 mL of methanol to quench the diphenylalkyl anion. The mixture was acidified with 9 g of ammonium chloride and the ammonia allowed to evaporate at room temperature. The residue was shaken with chloroform and water. The organic layer was dried and concentrated in vacuo to give 14.3 g of crude residue which, after chromatography on silica gel with chloroform as eluent, gave 13.9 g of 4,4-diphenylbut-1-ene which is characterized by:

Workup

  1. temperatureThe mixture was warmed
  2. temperatureto reflux
  3. customto quench excess lithium
  4. customto quench the diphenylalkyl anion
  5. customto evaporate at room temperature
  6. customThe organic layer was dried
  7. concentrationconcentrated in vacuo
  8. customto give 14.3 g of crude residue which

Sources & evidence

ORD record
ord-49512ef8ea2c47848dc671c71b095eea
Source dataset
uspto-grants-1995_02
Patent number
US05393797

Reaction notes

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