Question

What might be the reason why the bromobenzene substrate is added to the reaction flask in two portions rather than all at once?

Answer 1

Bromobenzene substrate is added in two portions rather than one. The reason for this is because adding it all at once would cause a decrease in phenylmagnesium bromide and increase in the product 1-phenylthanone. The synthesis of 1,1-diphenylethanol would not be able to occur without phenylmagnesium bromide.