Reacción #52781

Ecuación de reacción

Diethyl oxalate

potassium ethoxide

3-nitro-o-xylene

→

1-methyl-6-nitrophenylacetic acid

Rendimiento 45.0%

Disolventes

ether

ether

ether

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture was cooled in an ice bath
2. 2
   TemperaturaThe thick dark red mixture was refluxed for 0.5 hr
3. 3
   Concentraciónconcentrated
4. 4
   workup.ADDITIONtreated with 10% sodium hydroxide until almost all of the solid
5. 5
   workup.DISSOLUTIONdissolved
6. 6
   workup.ADDITIONHydrogen peroxide (30%) was then added to the dark red mixture until the red color
7. 7
   workup.ADDITIONThe mixture was treated alternately with 10% sodium hydroxide and 30% hydrogen peroxide until the dark red color
8. 8
   FiltraciónThe solid was filtered off
9. 9
   FiltraciónThe resulting precipitate was collected by vacuum filtration
10. 10
    Lavadowashed with water
11. 11
    Otrodried under vacuum

Procedimiento

Diethyl oxalate (30 mL) in 20 mL of dry ether was added with stirring to 19 g of potassium ethoxide suspended in 50 mL of dry ether. The mixture was cooled in an ice bath and 20 mL of 3-nitro-o-xylene in 20 mL of dry ether was slowly added. The thick dark red mixture was refluxed for 0.5 hr, concentrated, and treated with 10% sodium hydroxide until almost all of the solid dissolved. Hydrogen peroxide (30%) was then added to the dark red mixture until the red color changed to yellow. The mixture was treated alternately with 10% sodium hydroxide and 30% hydrogen peroxide until the dark red color was no longer present. The solid was filtered off and the filtrate acidified with 6 N hydrochloric acid. The resulting precipitate was collected by vacuum filtration, washed with water, and dried under vacuum to give 9.8 g (45% yield) of 1-methyl-6-nitrophenylacetic acid as an off-white solid. The solid was hydrogenated in methanol over 10% palladium on carbon to give 9.04 g of 4-methyl-2-oxindole as a white solid.

Fuente