Reacción #11028

Ecuación de reacción

2,4,6-trimethylbenzoyl chloride

lithium

naphthalene

hydrogen peroxide

P-chlorodiphenyl phosphine

→

title compound

2,4,6-trimethylbenzoyldiphenylphosphine oxide

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaWith occasional cooling
2. 2
   workup.STIRRINGAfter stirring for 4 hours
3. 3
   Filtraciónthe 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
   Temperaturacooling, at 10–20° C. over 1 hour
6. 6
   workup.STIRRINGthe mixture is then stirred for another 30 minutes
7. 7
   ConcentraciónThe 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
    Lavadowashed with an aqueous saturated sodium hydrogencarbonate solution
12. 12
    Secadodried over magnesium sulfate
13. 13
    Filtraciónfiltered
14. 14
    ConcentraciónThe filtrate is concentrated by evaporation in a Rotavap
15. 15
    OtroThe residue is crystallised from petroleum ether/ethyl acetate
16. 16
    Otrodried in a vacuum
17. 17
    Otrodrying oven at 40° C.

Procedimiento

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.

Fuente