Magnesium Bromide and Benzene would (Grignard reaction) be Phenyl Bromide Magnesium (Grignard Reagent). This is the starting block for many reactions. The initial step is the formation of the Grignard reagent, phenylmagnesium bromide, from the insertion of magnesium between the aryl and the halo groups.Br
Br reacted with Mg in THF yields MgBr (Phenyl Magnesium Bromide)
Benzene can be substituted for the THF as in your question with the same resulting product.
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