Reaktion #83843

Reaktionsgleichung

diethyl (2,5-dimethylphenyl)-hydroxymalonate

potassium hydroxide

→

2,5-dimethylmandelic acid

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenthe reaction was washed with diethyl ether
2. 2
   TemperaturAfter heating to 98° C. for a further 2 hours
3. 3
   Extraktionthe cooled materials was extracted into diethyl ether
4. 4
   TrocknenThe separated organic phase was dried over magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   Sonstigethe solvent was evaporated under reduced pressure
7. 7
   SonstigeRecrystallisation from toluene

Vorschrift

A sample of the diethyl (2,5-dimethylphenyl)-hydroxymalonate (21 parts) was reacted with a solution of potassium hydroxide (21 parts) in water (84 parts) at 98° C. for 5 hours. After cooling to ambient temperature, the reaction was washed with diethyl ether and acidified with 10M hydrochloric acid. After heating to 98° C. for a further 2 hours, the cooled materials was extracted into diethyl ether. The separated organic phase was dried over magnesium sulfate, filtered and the solvent was evaporated under reduced pressure. The crude amber coloured oil (15 parts) solidified on standing. Recrystallisation from toluene gave 2,5-dimethylmandelic acid (7 parts). The 1Hnmr, 13Cnmr and mass spectra were all consistent with the structure.

Quelle