Question

How will you synthesize benzoic acid from bromobenzene.

Answer 1

Hint: Before answering this question, one should know about benzoic acid and bromobenzene. Benzoic acid is an aromatic carboxylic acid. It is found naturally in many plants Bromobenzene is an unsaturated compound that can readily undergo an addition reaction.

Complete answer:
In this Grignard reagent, phenylmagnesium bromide is prepared with the help of bromobenzene and Mg metal in which diethyl ether is used as a solvent and there are some anhydrous conditions. The diethyl ether is used as a solvent to make Grignard reagents is important as the Partial positive charge on Mg in the Grignard reagent is stabilized by lone pairs of electrons on the oxygen to make sure it formed. In inert solvents, Grignard reagents are not formed. In nucleophilic addition reactions, diethyl ether or tetrahydrofuran functions well as a solvent because ether is not reactive with other reactants.

Phenyl magnesium bromide is then reacted with $C{{O}_{2}}$. After this, it will undergo hydrolysis and will give Benzoic acid.

Note:
The Carbon of the Grignard reagent shows two characteristics :
It acts as a nucleophile for the reaction with Carbon dioxide as a carbanion.
It acts as a strong base too as it reacts with acidic hydrogen atoms to give an alkane.
RMgX + HA = RH + MgAX
The structure of the Grignard reagent is represented as a partly ionic compound $\delta R...MgX\delta -+$Water, alcohols, terminal acetylenes, phenols, and carboxylic acids are some compounds that have acidic hydrogen and they will be readily donating a proton to destroy the reagent.