Question

Which of the following reactions will not give a primary amine?
(A) \[C{H_3}CON{H_2}\xrightarrow{{B{r_2}/KOH}}\]
(B) \[C{H_3}CN\xrightarrow{{LiA1{H_4}}}\]
(C) \[C{H_3}NC\xrightarrow{{LiA1{H_4}}}\]
(D) \[C{H_3}CON{H_2}\xrightarrow{{LiA1{H_4}}}\]

Answer 1

Hint: An amine is often a functional group with a lone pair on the nitrogen atom. Amines structurally mimic ammonia, where nitrogen can link with up to three hydrogen atoms. It is also defined by a number of carbon connectivity-based features.

Complete Step by Step Solution:
In order to know that when an alkyl or aryl group replaces one of the hydrogen atoms in the ammonia molecule, the presence of the primary amines can be determined. For instance: Methylamine \[{\text{ }}C{H_3}N{H_2}\]and Aniline \[{C_6}{H_5}N{H_2}\].
Let’s look the given options in the question to know that the reaction which will not give a primary amine:
First look at the option \[(A)\], as we know that the reaction \[C{H_3}CON{H_2}\xrightarrow{{B{r_2}/KOH}}\]represents the solution of acetamide. An acetamide belongs to the group of compounds known as acetamides, which are created when acetic acid and ammonia are formal condensationed. It belongs to the acetamide family and is a monocarboxylic acid amide, \[N - \]acylammonia, and. It is an acetimidic acid tautomer.
\[C{H_3}CON{H_2}\xrightarrow{{B{r_2}/KOH}}C{H_3}N{H_2}\]
It is primary amine.

Now consider the option \[(B)\], as we know that the reaction \[C{H_3}CN\xrightarrow{{LiA1{H_4}}}\]represents the solution of ethanenitrile. In refineries, ethanenitrile is primarily used as a solvent to remove impurities from butadiene. Acetonitrile is specifically supplied into the top of a distillation column that contains butadiene and other hydrocarbons. Butadiene is taken up by the acetonitrile as it is passes through the column and is then transferred from the bottom of the tower to an another separating tower. The butadiene is then separated using heat in the separating tower.
\[C{H_3}CN\xrightarrow{{LiA1{H_4}}}C{H_3}C{H_2}N{H_2}\]
It is primary amine.

Similarly, consider the option \[(C)\], as we know that the reaction \[C{H_3}NC\xrightarrow{{LiA1{H_4}}}\] represents the solution of methyl isocyanide. Isocyanomethane, also known as methyl isocyanide, is a chemical substance and a member of the isocyanide family. Although this colourless liquid and methyl cyanide are isomers, they respond quite differently. The fragrance of methyl isocyanide, like that of other simple volatile isocyanides, is distinctly intense and repulsive in contrast to the softly pleasant, ethereal aroma of acetonitrile.
\[C{H_3}NC\xrightarrow{{LiA1{H_4}}}C{H_3}NHC{H_3}\]
It is secondary amine.

The last option \[(D)\], as we know that the reaction \[C{H_3}CON{H_2}\xrightarrow{{LiA1{H_4}}}\] represents the solution of acetamide. The chemical equation is as follow:
\[C{H_3}CON{H_2}\xrightarrow{{LiA1{H_4}}}C{H_3}C{H_2}N{H_2}\]
It is primary amine.

Therefore, the correct option is: (C) \[C{H_3}NC\xrightarrow{{LiA1{H_4}}}\].

Note: It should be noted that an intermolecular interaction involves primary and secondary amines. This is because the nitrogen in one molecule and the hydrogen in another molecule form a hydrogen bond. Primary amines exhibit more of this intermolecular interaction than secondary amines.