How will you bring about the following conversions?

Benzene to biphenyl.

The conversion of benzene to biphenyl using Na and dry ether is called FITTIG reaction.

Firstly, the benzene is treated with Br2/FeBr3 results in the formation of bromobenzene. It is an electrophilic substitution. Further the bromobenzene is treated with Na metal in presence of dry ether to form biphenyl as the final product and NaBr as the by-product.

If instead of Na metal, bromobenzene is treated with Cu metal then the reaction is called Ullmann’s reaction. The final product obtained in this reaction will also be biphenyl.