Reaction #75455

Reaction equation

4-bromobiphenyl

iodine

hexabromobenzene

4-Bromobiphenyl

→

1,2,4,5-tetra-p-biphenylylbenzene

Solvents

THF

THF

THF

Conditions

Workup

1. 1
   Otherequipped with a condenser, a nitrogen inlet, an additional funnel and a magnetic stirring bar
2. 2
   Otherplaced in an additional funnel
3. 3
   Otherwas placed in a 50° C.
4. 4
   workup.ADDITIONwas added dropwise to the reaction
5. 5
   workup.ADDITIONAfter addition
6. 6
   Otherthe brownish reaction
7. 7
   Temperaturewas heated
8. 8
   Temperatureat reflux for another hour
9. 9
   workup.ADDITIONwas added dropwise from an additional funnel to the reaction
10. 10
    OtherThe reaction was quenched with ice and 8% hydrochloric acid
11. 11
    Extractionextracted with 400 mL of methylene chloride
12. 12
    WashThe organic layer was washed with saturated sodium chloride solution
13. 13
    Dryingdried over magnesium sulfate
14. 14
    OtherSolvent was evaporated
15. 15
    Washthe crude product was washed with hexane
16. 16
    Filtrationfiltered
17. 17
    Otherto give pure product

Procedure

Dry Mg turnings (3.9 g, 0.16 mol) and 30 mL of anhydrous THF were added to a 1 L 3-necked round-bottomed flask equipped with a condenser, a nitrogen inlet, an additional funnel and a magnetic stirring bar. 4-Bromobiphenyl (37.2 g, 0.16 mol) was dissolved in 150 mL of THF and placed in an additional funnel. The reaction flask was placed in a 50° C. oil bath and one crystal of iodine was added. Once the reaction started 4-bromobiphenyl was added dropwise to the reaction. After addition, the brownish reaction was heated at reflux for another hour and then cooled to room temperature. A suspension of hexabromobenzene (11.0 g, 0.02 mol) in 150 mL of THF was added dropwise from an additional funnel to the reaction and the mixture was stirred at room temperature overnight. The reaction was quenched with ice and 8% hydrochloric acid and extracted with 400 mL of methylene chloride. The organic layer was washed with saturated sodium chloride solution and dried over magnesium sulfate. Solvent was evaporated and the crude product was washed with hexane and filtered to give pure product.

Source