Question

Mendius reaction involves the;
(a) Reduction of aldehydes to give alcohols
(b) Reduction of nitriles with sodium and ethanol
(c) Oxidation of nitriles
(d) Hydrolysis of cyanide

Answer 1

Hint: Mendius reaction involves the reduction of the organic compound containing the cyanide group in the presence of an alkali metal and alcohol and results in the formation of the ammines. Now you can easily identify the reaction.

Complete answer:
> By the mendius reaction we mean, the reduction of the nitriles to the ammines. Now let’s first discuss what nitriles are.
> Nitriles are the compounds which consist of nitrogen atoms attached to the carbon atom through the triple bond. It is formed when the amides undergoes dehydration i.e. when amides are heated in the presence of the phosphorus oxide , it gets dehydrated and forms the nitrile. The reaction is supposed to occur as, $C{{H}_{3}}CON{{H}_{2}}\xrightarrow[-{{H}_{2}}O]{{{P}_{4}}{{O}_{10}}}C{{H}_{3}}CN$
>When this nitrile is made to react with the sodium atom in the presence of the alcohol , it undergoes reduction and nitrile is converted into the primary amines. This reduction of the nitriles into the ammines is called the mendius reaction. The reaction is supposed to occur as;
$\begin{align}
& R-CN\xrightarrow{Na+EtOH}RC{{H}_{2}}N{{H}_{2}} \\
& \text{ Mendius reduction} \\
\end{align}$

> So, this mendius reaction involves the reduction of nitriles with sodium and ethanol.

Hence, option (b) is correct.

Note: Don’t get confused in the amines and amides. Amines are the organic compounds which consist of the $-N{{H}_{2}}$ group in its compounds. On the other hand, Amides are the organic compounds which consist of the $-CON{{H}_{2}}$ group in its compounds.