4-Bromoanisole → Tris(4-methoxyphenyl)phosphine oxide

HRID 2180201Notes

Reaction equation

HRID 2180201 reaction equation
[Mg].Br[C:3]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][CH:4]=1.[O:11]=[P:12](Cl)(Cl)Cl>BrCCBr.C1COCC1>[CH3:10][O:9][C:6]1[CH:7]=[CH:8][C:3]([P:12](=[O:11])([C:3]2[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][CH:4]=2)[C:3]2[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[CH:5][CH:4]=2)=[CH:4][CH:5]=1

Participants

6

Reactant 3

HCID 77304-BromoanisoleHCID 24813Phosphorus oxychlorideHCID 5462224Magnesium

Product 1

HCID 3057506Tris(4-methoxyphenyl)phosphine oxideYield 89.1%

Reagents, catalysts & solvents 2

HCID 78391,2-DibromoethaneCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A reaction flask under nitrogen containing magnesium turnings (223.9 g, 9.21 mol) and 1950 mL THF was charged with 1 drop of 1,2-dibromoethane and heated to reflux for 1 h. Heating was removed and p-bromoanisole (1683 g, 9.00 mol) was added dropwise at a rate to maintain reflux. After holding the reaction mixture overnight, POCl3 (460.0 g, 3.00 mol) was added slowly over 2 h at 50-79° C. and the resulting mixture was held overnight at 50° C. The product was isolated by aqueous workup to give 984.5 g of tris(4-methoxyphenyl)phosphine oxide (89.0% yield). Recrystallized analytical specimen (from ethyl acetate): mp 145.2° C. (DSC), lit. 143-144° C. (J. Org. Chem. 1960, 25, 2001).

Workup

  1. temperatureheated
  2. temperatureto reflux for 1 h
  3. temperatureHeating
  4. customwas removed
  5. temperatureto maintain
  6. temperaturereflux
  7. additionwas added slowly over 2 h at 50-79° C.
  8. customThe product was isolated by aqueous workup

Sources & evidence

ORD record
ord-5ffe18a3640b4965bc7f2f7132cd1bff
Source dataset
uspto-grants-2005_05
Patent number
US06887950B2

Reaction notes

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