Question

What amides would you react with LiAlH₄ to form the following amines?

a. benzylmethylamine c. diethylamine

b. ethylamine d. triethylamine

Short answer

Lithium aluminum hydride is a strong reducing agent. It adds two hydride ions to the carbonyl carbon.

To prepare the given amine, we have to take an amide with one less carbon.

Step-by-step solution

Reduction by lithium aluminum hydride

Lithium aluminum hydride is a strong reducing agent. It adds two hydride ions to the carbonyl carbon.

To prepare the given amine, we have to take an amide with one less carbon.

 Step 2: Preparation of given amines

a) Preparation of (a)

When benzyl amide is treated with lithium aluminum hydride, it is converted into benzyl methanamine.

b) Preparation of (b)

When we treated methanamide with lithium aluminum hydride, it was converted into ethylamine.

c)

Preparation of (c)

When N-ethyl methanamide is treated with lithium aluminum hydride, it will convert into diethylamine.

d) Preparation of (d)

When diethyl methanamide is treated with lithium aluminum hydride, it is converted into trimethylamine.