Question

Butanenitrile may be prepared by heating -

• A. Butyl Alcohol with $\mathrm{KCN}$
• B. Propyl Alcohol with $\mathrm{KCN}$
• C. Butyl Chloride with $\mathrm{KCN}$
• D. Propyl Chloride with $\mathrm{KCN}$

Answer 1

The correct option is D

Propyl Chloride with $\mathrm{KCN}$

Explanation for correct option

(D)Propyl Chloride with $\mathrm{KCN}$

Preparation of butanenitrile

The reaction is as follows:-

${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{Cl}+\mathrm{KCN}\stackrel{∆}{\to }{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{CN}+\mathrm{KCl}$

So, Butanenitrile may be prepared by heating Propyl Chloride with $\mathrm{KCN}$.

Explanation for incorrect option

A.Butyl Alcohol does not react with $\mathrm{KCN}$ as hydroxyl groups cannot react with cyanide ions.

B.In the same way, Propyl Alcohol also does not react with $\mathrm{KCN}$.

C.The reaction of butyl chloride with $\mathrm{KCN}$ is as follows:-

${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{Cl}+\mathrm{KCN}\stackrel{∆}{\to }{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{CN}$

Butyl chloride on reaction with $\mathrm{KCN}$ result in the formation of Pentanenitrile.

Hence, options (A), (B), and (C) are incorrect.

Hence, option (D) is correct. Butanenitrile may be prepared by heating Propyl Chloride with $\mathrm{KCN}$.