Question

Primary amines react with esters to yield amides: RCO₂R^' + R^"NH₂ $\to$RCONHR^" + R^'OH . Propose a mechanism for the following reaction of an a b-unsaturated ester.

Short answer

When ester reacts with primary amine or ammonia in an acidic medium then they give amide as a product.

In this reaction, the first step includes a nucleophilic attack of nitrogen on the carbonyl center followed by proton transfer and the alcohol portion of ester is lost.

Step-by-step solution

Reaction of primary amine and ester to give amide

When ester reacts with primary amine or ammonia in an acidic medium then they give amide as a product.

In this reaction, the first step includes a nucleophilic attack of nitrogen on the carbonyl center followed by proton transfer and the alcohol portion of ester is lost.

Mechanism of the given reaction

In the given reaction first, the lone pair of nitrogen attack the double-bonded carbon and further rearrangements take place as shown below;

In the next step, intramolecular rearrangements take place. Lone pair of nitrogen attacks the carbonyl carbon and we get the desired product.