Within this study, the Grignard reagent formation of phenylmagnesium bromide 2 from bromobenzene 1 was used for the determination of residence time distributions under reactive conditions and the Grignard reagent formation of benzylmagnesium bromide 5 from (bromomethyl)benzene 4 was performed to study the impact on selectivity. Halides used and their corresponding Grignard reagent and Wurtz coupling product are displayed in figure . The synthesis of phenylmagnesium bromide from bromobenzene was chosen to determine the residence time distribution under reactive conditions due to the following reasons: