4-Bromoanisole → Bis(4-methoxyphenyl)-2,4,5-trimethylphenylphosphine oxide

HRID 2180205Notes

Reaction equation

HRID 2180205 reaction equation
[Mg].Br[C:3]1[C:4]([CH3:11])=[CH:5][C:6]([CH3:10])=[C:7]([CH3:9])[CH:8]=1.Br[C:13]1[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=1.[O:21]=[P:22](Cl)(Cl)Cl>C1COCC1.BrCCBr>[CH3:20][O:19][C:16]1[CH:17]=[CH:18][C:13]([P:22](=[O:21])([C:13]2[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=2)[C:3]2[CH:8]=[C:7]([CH3:9])[C:6]([CH3:10])=[CH:5][C:4]=2[CH3:11])=[CH:14][CH:15]=1

Participants

7

Reactant 4

HCID 77304-BromoanisoleHCID 24813Phosphorus oxychlorideHCID 796101-Bromo-2,4,5-trimethylbenzeneHCID 5462224Magnesium

Product 1

HCID 22290123Bis(4-methoxyphenyl)-2,4,5-trimethylphenylphosphine oxideYield 79.2%

Reagents, catalysts & solvents 2

HCID 78391,2-DibromoethaneCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

A reaction flask under nitrogen containing magnesium turnings (120 g, 4.94 mol) and 412 mL THF was charged with 0.5 g of 1,2-dibromoethane and heated to reflux for 1 h. A separate flask was charged with 5-bromo-1,2,4-trimethylbenzene (300 g, 1.51 mol), dissolved in 568 mL of THF. The heat was removed from the first flask and the 5-bromo-1,2,4-trimethylbenzene solution was added dropwise at a rate to maintain reflux. 4-Bromoanisole (536.7 g, 3.01 mol) was then added over 1.5 h at 75° C. reaction temperature. After holding the reaction mixture overnight, POCl3 (231 g, 1.51 mol) was added dropwise at 40-80° C. The product mixture was isolated by aqueous workup to give 453.6 g (79% yield) of product mixture as a viscous liquid. The structure was consistent with NMR data.

Workup

  1. temperatureheated
  2. temperatureto reflux for 1 h
  3. customThe heat was removed from the first flask
  4. additionthe 5-bromo-1,2,4-trimethylbenzene solution was added dropwise at a rate
  5. temperatureto maintain
  6. temperaturereflux
  7. customreaction temperature
  8. additionwas added dropwise at 40-80° C
  9. customThe product mixture was isolated by aqueous workup

Sources & evidence

ORD record
ord-401017bf492a4095b144042c651548be
Source dataset
uspto-grants-2005_05
Patent number
US06887950B2

Reaction notes

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