Reacción #1061906

Ecuación de reacción

acetic anhydride

2,4-di-tert-butylphenol

glyoxylic acid

water

→

3-acetoxy-5,7-di-tert-butyl-3H-benzofuran-2-one

Rendimiento 92.0%

Disolventes

tert-butyl methyl ether

1,2-dichloroethane

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónAfterwards the reaction mixture is concentrated on a vacuum rotary evaporator
2. 2
   Temperaturathe solution is refluxed for 90 minutes
3. 3
   Lavadowashed in succession with water and dilute sodium hydrogencarbonate solution
4. 4
   OtroThe aqueous phases are separated
5. 5
   Extracciónextracted with 50 ml of tert-butyl methyl ether
6. 6
   Secadodried over magnesium sulfate
7. 7
   Concentraciónconcentrated on a vacuum rotary evaporator

Procedimiento

A mixture of 21.2 g (0.10 mol) of 2,4-di-tert-butylphenol (97%), 16.3 g (0.11 mol) of 50% aqueous glyoxylic acid and 0.05 g (0.26 mmol) of p-toluenesulfonic acid monohydrate in 30 ml of 1,2-dichloroethane is refluxed under nitrogen for 3.5 hours on a water separator. Afterwards the reaction mixture is concentrated on a vacuum rotary evaporator. The residue is taken up in 9.9 ml (0.105 mol) of acetic anhydride and the solution is refluxed for 90 minutes. The reaction mixture is then cooled to room temperature, diluted with 100 ml of tert-butyl methyl ether and washed in succession with water and dilute sodium hydrogencarbonate solution. The aqueous phases are separated and extracted with 50 ml of tert-butyl methyl ether. The organic phases are combined, dried over magnesium sulfate and concentrated on a vacuum rotary evaporator. Chromatography of the residue on silica gel with the solvent system dichloromethane/hexane=2:1 yields 28.0 g (92%) of 3-acetoxy-5,7-di-tert-butyl-3H-benzofuran-2-one (compound (206), Table 2) as a thick reddish resin.

Fuente