Reaktion #464358

Reaktionsgleichung

Magnesium

iodine crystals

bromide

magnesium

Phenylpropylmagnesium bromide

hydrochloric acid

Diethylchlorophosphite

Phenylpropyl bromide

→

3-phenylpropylphosphinic acid

Ausbeute 53.2%

Lösungsmittel

diethyl ether

water

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAfter several minutes the iodine was consumed
2. 2
   workup.ADDITIONadditional phenylpropyl bromide was added
3. 3
   Sonstige(1.5 hours)
4. 4
   Sonstigewas sealed
5. 5
   Sonstigestored at 5° C
6. 6
   Temperaturwhile maintaining a temperature between 0-10° C
7. 7
   SonstigeA thick white slurry formed
8. 8
   workup.STIRRINGwas stirred an additional 30 minutes
9. 9
   FiltrationThe mixture was filtered under a nitrogen atmosphere
10. 10
    Sonstigethe filtrate evaporated under reduced pressure
11. 11
    Sonstigeto give a clear and colorless liquid
12. 12
    SonstigeAn exothermic reaction
13. 13
    workup.STIRRINGstirring
14. 14
    Extraktionfollowed by extraction with ethyl acetate
15. 15
    Waschenwashed with brine
16. 16
    Trocknendried (MgSO4)
17. 17
    Sonstigeevaporated
18. 18
    workup.ADDITIONTo the clear liquid was added sodium hydroxide (40 mL, 2.0 M NaOH)
19. 19
    workup.STIRRINGthe resulting solution stirred for 1 hour
20. 20
    Waschenwashed with diethyl ether
21. 21
    Extraktionextracted twice with ethyl acetate
22. 22
    Trocknendried (MgSO4)
23. 23
    Sonstigeevaporated

Vorschrift

Magnesium turnings (2.44 g, 0.10 mol) in 20 mL of dry diethyl ether under an atmosphere of nitrogen was added several iodine crystals. Phenylpropyl bromide (20.0 g, 0.10 mol) in 80 mL of diethyl ether was placed in a dropping funnel. Approximately 10 mL of the bromide solution was added to the magnesium turnings and stirring was initiated. After several minutes the iodine was consumed and additional phenylpropyl bromide was added while maintaining a temperature of 35° C. Once additional was complete (1.5 hours) the mixture was sealed and stored at 5° C. Diethylchlorophosphite (15.7 g, 0.1 mol) in 50 mL of dry diethyl ether was cooled to 5° C. under an atmosphere of nitrogen. Phenylpropylmagnesium bromide (100 mL, 0.1 mol, 1.0 M solution of in Et2O) was added dropwise over 2 hours while maintaining a temperature between 0-10° C. A thick white slurry formed and was stirred an additional 30 minutes. The mixture was filtered under a nitrogen atmosphere and the filtrate evaporated under reduced pressure to give a clear and colorless liquid. To the liquid was added 20 mL of water followed by 0.5ml of concentrated hydrochloric acid. An exothermic reaction was observed and stirring continued for 20 minutes followed by extraction with ethyl acetate. The organics were combined, washed with brine, dried (MgSO4) and evaporated. To the clear liquid was added sodium hydroxide (40 mL, 2.0 M NaOH), the resulting solution stirred for 1 hour and then washed with diethyl ether. The aqueous layer was acidified to pH 1.0 with concentrated hydrochloric acid and extracted twice with ethyl acetate. The organics were combined, dried (MgSO4) and evaporated to give 3-phenylpropylphosphinic acid (1,R=CH2CH2CH2Ph,R1=H)(9.8 g, 53%) as a clear and colorless oil.

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