Reaktion #11028

Reaktionsgleichung

2,4,6-trimethylbenzoyl chloride

lithium

naphthalene

hydrogen peroxide

P-chlorodiphenyl phosphine

→

title compound

2,4,6-trimethylbenzoyldiphenylphosphine oxide

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturWith occasional cooling
2. 2
   workup.STIRRINGAfter stirring for 4 hours
3. 3
   Filtrationthe red solution is filtered via a glass frit (G2 porosity) into a sulfonation flask with exclusion of moisture and
4. 4
   workup.STIRRINGwith stirring
5. 5
   Temperaturcooling, at 10–20° C. over 1 hour
6. 6
   workup.STIRRINGthe mixture is then stirred for another 30 minutes
7. 7
   EinengenThe organic phase is concentrated by evaporation in a Rotavap
8. 8
   workup.ADDITIONcharged
9. 9
   workup.STIRRINGafter stirring for 30 minutes
10. 10
    workup.ADDITIONThe reaction emulsion is poured on water
11. 11
    Waschenwashed with an aqueous saturated sodium hydrogencarbonate solution
12. 12
    Trocknendried over magnesium sulfate
13. 13
    Filtrationfiltered
14. 14
    EinengenThe filtrate is concentrated by evaporation in a Rotavap
15. 15
    SonstigeThe residue is crystallised from petroleum ether/ethyl acetate
16. 16
    Sonstigedried in a vacuum
17. 17
    Sonstigedrying oven at 40° C.

Vorschrift

Under argon and with exclusion of moisture, 2.76 g of lithium (0.40 mol) are suspended at room temperature in 100 ml of THF and this suspension is charged with 0.10 g (0.00078 mol) of naphthalene. This mixture is then stirred for 10 minutes at room temperature. With occasional cooling and vigorous stirring, 45.2 g (0.0 mol) of P-chlorodiphenyl phosphine are added dropwise to the dark brown suspension at 10–25° C. After stirring for 4 hours, 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. 38.0 g (0.2 mol) of 2,4,6-trimethylbenzoyl chloride are added dropwise, with stirring and cooling, at 10–20° C. over 1 hour and the mixture is then stirred for another 30 minutes. The organic phase is concentrated by evaporation in a Rotavap and the residue is taken up in 100 ml of toluene and charged, with vigorous stirring at a temperature from 50–60° C., with 23.0 g (0.20 mol) of hydrogen peroxide (30%). The reaction is complete after stirring for 30 minutes. 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 crystallised from petroleum ether/ethyl acetate and dried in a vacuum drying oven at 40° C., yielding 55.0 g (79% of theory) of the title compound in the form of a yellow powder having a melting point of 89–90° C.

Quelle