Réaction #94984

Équation de réaction

sodium hydroxide

bis(4-methoxyphenyl)phosphine-oxide

trichlorosilane

sodium hydroxide

phosphine oxide

→

bis-(4-methoxyphenyl)phosphine

Rendement 57.0%

Solvants

toluene

Conditions de réaction

Traitement

1. 1
   AutreThis resulted
2. 2
   Températurein moderate heat
3. 3
   TempératureThe mixture was heated at 90° for 5 h, whereupon the clear colorless solution
4. 4
   Températurewas cooled to 0°
5. 5
   Températurewhile cooling the mixture in an ice-bath
6. 6
   Autrethe vigorous reaction
7. 7
   workup.DISSOLUTIONdissolved (30-90 min)
8. 8
   Autreleaving two clear
9. 9
   Autreto separate
10. 10
    ExtractionThe aqueous layer was extracted with 2×20 mL of toluene
11. 11
    SéchageThe combined toluene extracts were dried
12. 12
    Autre(deoxygenated brine and sodium sulfate)
13. 13
    Filtrationfiltered
14. 14
    Autrestripped of solvent on the rotary evaporator at 80°/5 mm Hg
15. 15
    Autreto give 1.11 g (84.5%) of crude product
16. 16
    workup.DISTILLATIONThe thick oil was distilled by bulb to bulb distillation at 115°-135°/0.02 mm Hg for 1 h

Mode opératoire

A solution-suspension of 1.4 g (5.34 mmol) of bis(4-methoxyphenyl)phosphine-oxide in 18 mL of toluene was treated under argon with 3.35 g (2.5 mL, 25 mmol) of trichlorosilane in one portion. This resulted in moderate heat and gas evolution and led to complete solution of the phosphine oxide. The mixture was heated at 90° for 5 h, whereupon the clear colorless solution was cooled to 0°. With vigorous stirring, 8.0 mL of 2 N aqueous sodium hydroxide solution (16 mmol) was added slowly while cooling the mixture in an ice-bath to moderate the vigorous reaction. When all the sodium hydroxide had been added, the mixture was allowed to warm to room temperature and stirred vigorously until all solid dissolved (30-90 min), leaving two clear, colorless liquid phases. The layers were allowed to separate and the toluene layer was drawn off under argon via a cannula. The aqueous layer was extracted with 2×20 mL of toluene. The combined toluene extracts were dried (deoxygenated brine and sodium sulfate), filtered, and stripped of solvent on the rotary evaporator at 80°/5 mm Hg to give 1.11 g (84.5%) of crude product. The thick oil was distilled by bulb to bulb distillation at 115°-135°/0.02 mm Hg for 1 h to give 0.747 g (57%) of bis-(4-methoxyphenyl)phosphine as a colorless thick oil which shortly crystallized to colorless, slightly greasy crystals.

Source