Reaktion #11027

Reaktionsgleichung

hydrogen peroxide

sodium

ditolylphosphine chloride

2,4,6-trimethylbenzoyl chloride

→

title compound

2,4,6-trimethylbenzoylditolylphosphine oxide

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring for 12 h
2. 2
   Filtrationthe red solution is filtered via a glass frit (G2 porosity) into a sulfonation flask with exclusion of moisture and
3. 3
   workup.STIRRINGWith stirring
4. 4
   Temperaturcooling
5. 5
   workup.STIRRINGAfter stirring for another 2 hours
6. 6
   workup.ADDITIONthe brownish-red reaction suspension is poured on water
7. 7
   Extraktionextracted with toluene
8. 8
   TrocknenThe organic phase is dried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated by evaporation in a rotary evaporator (Rotavap)
11. 11
    workup.STIRRINGafter stirring for 2 hours at a temperature from 50–60° C
12. 12
    workup.ADDITIONThe reaction emulsion is poured on water
13. 13
    Waschenwashed with an aqueous saturated sodium hydrogencarbonate solution
14. 14
    Trocknendried over magnesium sulfate
15. 15
    Filtrationfiltered
16. 16
    EinengenThe filtrate is concentrated by evaporation in a Rotavap
17. 17
    SonstigeThe residue is purified over silica gel
18. 18
    Sonstigedried under high vacuum

Vorschrift

Under argon and with exclusion of moisture, 4.6 g of chopped sodium (0.20 mol) are placed at room temperature in 100 ml of tetrahydrofuran. Stirring slowly, 24.9 g (0.10 mol) of ditolylphosphine chloride (isomeric mixture of di-ortho, di-para and ortho-para) are added dropwise at 20–25° C. After stirring for 12 h, the red solution is filtered via a glass frit (G2 porosity) into a sulfonation flask with exclusion of moisture and using argon as protective gas. With stirring and cooling, 19.0 g (0.105 mol; 5% excess) of 2,4,6-trimethylbenzoyl chloride are added dropwise over 30 minutes at room temperature. After stirring for another 2 hours, the brownish-red reaction suspension is poured on water and extracted with toluene. The organic phase is dried over magnesium sulfate, filtered and concentrated by evaporation in a rotary evaporator (Rotavap). The resulting phosphine has a 23.24 ppm shift in the 31P-NMR spectrum. The residue is taken up in 100 ml of toluene and charged with 11.5 g (0.10 mol) of hydrogen peroxide (30%). The reaction is complete after stirring for 2 hours at a temperature from 50–60° C. The reaction emulsion is poured on water and washed with an aqueous saturated sodium hydrogencarbonate solution and then dried over magnesium sulfate and filtered. The filtrate is concentrated by evaporation in a Rotavap. The residue is purified over silica gel and dried under high vacuum, yielding 33.8 g (90% of theory) of the title compound in the form of a yellow viscous oil. The 31P-NMR shift is 14.54 ppm.

Quelle