Reaktion #214334

Reaktionsgleichung

p-anisidine

2-methyl-2-hydroxy-butan-3-one

acetic acid

toluene

→

5-methoxy-2,3,3-trimethyl-indolenine

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONThe solvent is then distilled off
2. 2
   TemperaturAfter cooling to 160° C.
3. 3
   workup.ADDITION10 parts of concentrated sulfuric acid are added
4. 4
   workup.DISTILLATIONwhilst distilling off the water
5. 5
   Sonstigeformed
6. 6
   workup.DISTILLATIONDistillation under reduced pressure (21 mbar)

Vorschrift

246 parts of p-anisidine, 204 parts of 2-methyl-2-hydroxy-butan-3-one and 10 parts of acetic acid in 650 parts of toluene are heated, with removal of water from the system, until no more water separates off. The solvent is then distilled off and the residue is heated for 5 hours at 220° C. After cooling to 160° C., 10 parts of concentrated sulfuric acid are added; the mixture is kept at 160° C. for 3 hours, whilst distilling off the water formed. Distillation under reduced pressure (21 mbar) gives 318.7 parts of 5-methoxy-2,3,3-trimethyl-indolenine (melting point 53°-54° C.), corresponding to 84.3% of theory.

Quelle