Question

How will the following conversion be carried out?
Chloroethane to propan-1-amine.

Answer 1

Hint: Whenever we need to increase one carbon atom we always use cyanide as a reagent. Then we will do the reduction of cyanide to form amine.

Complete step by step solution:
The molecular formula for chloroethane is $ {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{Cl}} $
The molecular formula for prop-1-amine is $ {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{C}}{{\text{H}}_2}{\text{N}}{{\text{H}}_2} $
To do the required conversion we are required to add one more carbon atom. For this we will first do the nucleophilic substitution reaction using potassium cyanide to convert ethyl chloride to ethyl cyanide. The reaction occurs as:
 $ {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{Cl}} + {\text{KCN}} \to {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{CN}} $
Now we will reduce the ethyl cyanide. Reduction is the process of addition of hydrogen to any species. We will use reducing agents such as lithium aluminium hydride for the conversion of ethyl cyanide to prop-1-amine, the reaction occurs as follow:
 $ {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{CN}} + {\text{LiAl}}{{\text{H}}_4} \to {\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{C}}{{\text{H}}_2}{\text{N}}{{\text{H}}_2} $

Additional information
Ethyl chloride is a haloalkane. It is a flammable gas. It has a variety of uses. It is used as a refrigerant, spray and aesthetic. Lithium aluminium hydride is an organometallic reagent which is used as reducing agents. It is a very good reducing agent and is mainly used in the reduction of esters and carboxylic acid. It has a weaker aluminium hydrogen bond and hence easily leaves hydrogen and hence acts as a good reducing agent. It is commonly abbreviated as LAH. It is also used as a source of storage of hydrogen.

Note:
Potassium cyanide is a crystalline solid and is highly soluble in water. Both potassium cyanide and sodium cyanide are used in synthesis of various organic products. The cyanides compounds are poisonous and toxic in nature.