Reaktion #334361

Reaktionsgleichung

6,8-dimercapto octanoic acid

sodium hydroxide

sodium hydroxide

→

1,2-dithiolane-3-pentanoic acid

Ausbeute 75.3%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe solution formed
2. 2
   ExtraktionThe solution was extracted twice
3. 3
   Sonstigeeach time with 30 ml of methyl tertiary butyl ether, the aqueous solution separated off
4. 4
   Sonstigethe residual ether removed in a vacuum
5. 5
   workup.ADDITIONThe solution was diluted with 200 ml of water, 7 mg of iron (III) sulfate
6. 6
   workup.ADDITIONadded
7. 7
   Filtrationthe precipitated iron salt filtered off
8. 8
   Sonstigewas acidified with 10% hydrochloric acid at 5° C., to 10° C.
9. 9
   workup.STIRRINGfurther stirred for 1 hour at pH 1
10. 10
    Sonstigethe precipitated crude product
11. 11
    Filtrationfiltered off
12. 12
    WaschenThe precipitate was washed with water
13. 13
    Sonstigedried in a vacuum
14. 14
    Sonstigerecrystallized from ethyl acetate/hexane
15. 15
    SonstigeAfter drying there

Vorschrift

8.0 grams (0.038 mole) of 6,8-dimercapto octanoic acid were added to 1.54 grams (0.038 mole) of sodium hydroxide in 90 ml of water and the solution formed adjusted to pH 9 with dilute aqueous sodium hydroxide. The solution was extracted twice, each time with 30 ml of methyl tertiary butyl ether, the aqueous solution separated off and the residual ether removed in a vacuum. The solution was diluted with 200 ml of water, 7 mg of iron (III) sulfate added and oxygen led in with stirring at room temperture. After 2.5 hours the reaction solution had reached a pH of 12.4, the supply of oxygen was ended and the precipitated iron salt filtered off. The clear yellow solution was acidified with 10% hydrochloric acid at 5° C., to 10° C., further stirred for 1 hour at pH 1 and the precipitated crude product filtered off. The precipitate was washed with water, dried in a vacuum and recrystallized from ethyl acetate/hexane. After drying there were obtained 5.9 grams (75% of theory) of 1,2-dithiolane-3-pentanoic acid as yellow crystals having a melting point of 61° C. to 62° C.

Quelle