Reaktion #460470

Reaktionsgleichung

oxygen

1,4-diiodobenzene

iodotrifluoroethylene

→

1,4-BIS(TRIFLUOROVINYL)BENZENE

Ausbeute 65.0%

Lösungsmittel

Glyme

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 5 liter 3-necked round bottom flask is fitted with a mechanical stirrer
2. 2
   Temperatura nitrogen padded reflux condenser
3. 3
   SonstigeThe flask is then purged with nitrogen for 15 minutes
4. 4
   Sonstigeget
5. 5
   Temperaturwarm
6. 6
   workup.WAITAfter 2 hours a white precipitate begins
7. 7
   Sonstigeto form
8. 8
   workup.STIRRINGAfter stirring
9. 9
   Temperaturwithout heat for 4 hours
10. 10
    Sonstigepurge
11. 11
    workup.STIRRINGThe mixture is stirred overnight
12. 12
    Sonstigeresulting in the formation of a large amount of suspended solid
13. 13
    workup.STIRRINGto stir an additional 24 hours
14. 14
    Filtrationafter which it is filtered
15. 15
    Waschenthe precipitate is washed with hexane (3 times with 50 ml each wash)
16. 16
    Sonstigeevaporated at 30° C. on a rotary evaporator
17. 17
    Sonstigeto provide a residue which
18. 18
    Sonstigeis purified by column chromatography (neutral alumina, hexane eluent)
19. 19
    Sonstigeto give 7.50 g of CF2 =CF--Ph--CF=CF2 as product (0.0315 mole, 65% yield)
20. 20
    Sonstigegives the following spectrum
21. 21
    workup.WAITif left

Vorschrift

A 5 liter 3-necked round bottom flask is fitted with a mechanical stirrer, a nitrogen padded reflux condenser and a rubber septum. Glyme (100 ml) and activated zinc granules (11.50 g, 0.18 mole) are added to the flask along with a magnetic stirring bar. The flask is then purged with nitrogen for 15 minutes, after which time iodotrifluoroethylene (20.3 g, 0.098 mole) is added slowly via syringe through the septum. After 20 minutes of stirring the mixture begins to turn brown and get warm. After 2 hours a white precipitate begins to form. After stirring is continued without heat for 4 hours, the flask is opened under a slow nitrogen purge and 1,4-diiodobenzene (16.0 g, 0.0485 mole) ia added along with palladium tetrakis(triphenylphosphine) (0.57 g, 0.00049 mole). The mixture is stirred overnight, resulting in the formation of a large amount of suspended solid. The reaction is allowed to stir an additional 24 hours, after which it is filtered, and the precipitate is washed with hexane (3 times with 50 ml each wash). The filtrates are combined and evaporated at 30° C. on a rotary evaporator to provide a residue which is purified by column chromatography (neutral alumina, hexane eluent) to give 7.50 g of CF2 =CF--Ph--CF=CF2 as product (0.0315 mole, 65% yield). This product is analysed by GC/MS and gives the following spectrum: m/e: 238 (100%); 188 (12.0%); 187 (46.4%); 169 (92.0%); 138 (18.8%); 99 (16.3%); 81 (12.3%); 69 (30.1%). The material is found to be air sensitive, fuming acid gasses if left exposed to oxygen.

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