Reaction of N-Butyl Chloride Treatment (NEET Chemistry)

What happens when:

(A) n- butyl chloride is treated with alcoholic KOH.

(B) Bromobenzene is treated with Mg in the presence of dry ether.

(C) Chlorobenzene is subjected to hydrolysis

(D) Ethyl chloride is treated with aqueous

(E) Methyl bromide is treated with sodium in the presence of dry ether.

(F) Methyl chloride is treated with KCN.

Hint: We’ll go through each reaction step by step to observe the outcomes. As we know, alcoholic KOH acts as a reducing agent and will therefore reduce the haloalkane. Additionally, when chlorobenzene undergoes hydrolysis, phenol is produced.

Complete Answer:

(A) When n- butyl chloride reacts with alcoholic KOH, the product formed is butene. This reaction is known as hydrohalogenation.

 Here is the reaction in LaTeX format:

$C{H}_3-C{H}_2-C{H}_2-C{H}_2-Cl\underset{Dehydrogenation}{\overset{KOH\left(alc\right)}{\to }}C{H}_3-C{H}_2-C{H}_2=C{H}_2+H_{2}O$

(B) The reaction of bromobenzene with Mg in the presence of dry ether, the product of this reaction is Phenylmagnesium bromide

$Ph-Br+Mg\underset{}{\overset{dryether}{\to }}Ph-MgBr$ 

(C) The hydrolysis of chlorobenzene is not possible under normal conditions. In order to subject chlorobenzene for hydrolysis, we need to heat chlorobenzene in an aqueous medium with sodium hydroxide solution at temperature 623K and a pressure of 300 atm to form phenol.

$Ph-Cl\underset{H^{+}}{\overset{NaOH,623K,300atm}{\to }}Ph-OH$  

(D) The reaction of ethyl chloride with aqueous KOH, the product formed is ethanol

$C{H}_3-C{H}_2-Cl\underset{\left(hydrolysis\right)}{\overset{KOH\left(aq\right)}{\to }}C{H}_3-C{H}_2-OH+KCl$ 

(E) The reaction of methyl bromide with sodium in the presence of dry ether yields ethane. This reaction is also known as the wurtz reaction.

$2C{H}_3-Br+2Na\underset{\left(wurtzreaction\right)}{\overset{Dryether}{\to }}C{H}_3-C{H}_3+2NaBr$

(F) The reaction of methyl chloride with KCN, the product formed is methyl cyanide. This reaction is a substitution reaction.

$C{H}_3-Cl+KCN\underset{Nucleophilicsubstitution}{\overset{}{\to }}C{H}_3-CN+KCl$

 Note: The reactions mentioned above are examples of named reactions, specifically known as Wurtz reactions, which are utilized to synthesize symmetrical alkanes. Additionally, keep in mind that aqueous KOH is applied when the reactant undergoes hydrolysis, whereas alcoholic KOH serves as a strong base. For instance, in the reaction above, we convert the alkyl halide to an alkene using alcoholic KOH. However, when we use aqueous KOH with an alkyl halide, the resulting product will be an alcohol containing the -OH functional group.