Question

Give the structures of the carbonyl compound and the amine used to form the following imines.

(a)

(b)

(c)

(d)

(e)

(f)

Short answer

(a)

(b)

(c)

(d)

(e)

(f)

Step-by-step solution

Imines

Ammonia or primary amine under proper conditions reacts with a ketone or an aldehyde to form an imine.

Mechanism of imine formation

The mechanism of imine formation is a type of acid catalyzed nucleophlic addition of an amine to the carbonyl group.The fist step is the attack of an amine to an aldehyde or ketone which is followed by deprotonation of the nirogen atom that gives an unstable intermediate known as the carbinolamine. Second step is the conversion of carbinolamine to imine by loss of a water molecule. The formation of imine is a reversible process and most imines can be hydrolysed back into the amines and aldehydes or ketones.

Structures of carbonyl compound and the amine

(a)

(b)

(c)

(d)

(e)

(f)