Reaktion #1362629

Reaktionsgleichung

sodium hydroxide

6-acetyl-3,3,5,8-tetramethylthiochroman-4-one

iodine

potassium hydroxide

→

title compound

Ausbeute 95.0%

6-Carboxy-3,3,5,8-tetramethylthiochroman-4-one

Ausbeute 95.0%

Lösungsmittel

pyridine

pyridine

water

ethylene glycol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated at 110~110° C. for 6 hours
2. 2
   workup.DISTILLATIONwas distilled off under reduced pressure
3. 3
   TemperaturThe mixture was refluxed
4. 4
   Temperaturunder heat for 2 hours
5. 5
   Temperaturto cool
6. 6
   Waschenan aqueous layer was washed with chloroform twice
7. 7
   FiltrationA precipitated grey solid was collected by filtration under reduced pressure
8. 8
   Waschenwashed with water
9. 9
   Sonstigedried under reduced pressure

Vorschrift

A mixture containing 10.8 g (41 mmol) of 6-acetyl-3,3,5,8-tetramethylthiochroman-4-one, 12.6 g (50 mmol) of iodine and 9.8 g (124 mmol) of pyridine was heated at 110~110° C. for 6 hours. After the completion of the reaction, excess pyridine was distilled off under reduced pressure, and to the residue were added 50 ml of ethylene glycol, 20 ml of water and 11 g (167 mmol) of potassium hydroxide. The mixture was refluxed under heat for 2 hours. After the reaction mixture was allowed to cool, 200 ml of a 1 wt % sodium hydroxide aqueous solution was added, and an aqueous layer was washed with chloroform twice and then acidified with a 5 wt % hydrochloric acid aqueous solution. A precipitated grey solid was collected by filtration under reduced pressure, washed with water and then dried under reduced pressure to give 10.3 g (yield 95%) of the title compound.

Quelle