Reacción #334361

ord-1bf2dee881c547ac8266ebe59e14e576

Disolventes

Condiciones de reacción

Condiciones detalladas
See reaction.notes.procedure_details.

Tratamiento posterior

  1. 1
    Otrothe solution formed
  2. 2
    ExtracciónThe solution was extracted twice
  3. 3
    Otroeach time with 30 ml of methyl tertiary butyl ether, the aqueous solution separated off
  4. 4
    Otrothe 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
    Filtraciónthe precipitated iron salt filtered off
  8. 8
    Otrowas acidified with 10% hydrochloric acid at 5° C., to 10° C.
  9. 9
    workup.STIRRINGfurther stirred for 1 hour at pH 1
  10. 10
    Otrothe precipitated crude product
  11. 11
    Filtraciónfiltered off
  12. 12
    LavadoThe precipitate was washed with water
  13. 13
    Otrodried in a vacuum
  14. 14
    Otrorecrystallized from ethyl acetate/hexane
  15. 15
    OtroAfter drying there

Procedimiento

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.

Fuente

DOI: 10.6084/m9.figshare.5104873.v1Patente: US04705867uspto-grants-1987_11