Question

What is the end product that is formed when Phenyl Magnesium Bromide reacts with t-butanol?

Answer 1

Acid-base reaction

The reaction between Grignard reagent with alcohol is a type of acid-base reaction.

The reaction involves the acidic nature of $\mathrm{O}-\mathrm{H}$ bonds of the alcohols, as the bonds remove hydrogen.

Explanation

Grignard Reagent: A Grignard reagent is an organomagnesium halide having a formula of RMgX, where X is a halogen (-Cl, -Br, or -I), and R is an alkyl or aryl (based on a benzene ring) group.

The general reaction of the Grignard reagent with alcohol

• R−MgX+HO−R’→R−H+XMgOR’

The reaction of Phenyl Magnesium Bromide with t-butanol

• When Phenyl Magnesium Bromide reacts with t-butanol, benzene is obtained as the product.
• As for the reaction process, it forms benzene because the phenyl group is an electronegative group.
• It is associated with the active hydrogen of alcohol that is, -H of -OH group of alcohol.
• Thus, we can also state that Grignard reagents tend to react with compounds that contain active hydrogen to give hydrocarbons that correspond to the alkyl (or aryl) part of the Grignard reagent.

${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{MgBr}\left(\mathrm{aq}\right)+{\left({\mathrm{CH}}_3\right)}_3\mathrm{COH}\left(\mathrm{aq}\right)\to {\mathrm{C}}_6{\mathrm{H}}_6\left(\mathrm{aq}\right)+{\left({\mathrm{CH}}_3\right)}_3\mathrm{COMgBr}\left(\mathrm{aq}\right)$

The mechanism for the reaction is,