Question

Write the name of reaction
\begin{align*} CH_{3}COOH+HN_{3}\xrightarrow{H_{2}SO_{4}}CH_{3}NH_{2}+CO_{2}+N_{2}
\end{align*}

Answer 1

Hint: This is a kind of reaction which includes hydrazoic acid($HN_3$) reacting with carboxylic acid to give amine along with the removal of nitrogen gas. It is clear that this is a rearrangement reaction.

Complete answer:
- The reaction mentioned above is the Schmidt reaction. It is an important name reaction of organic chemistry.
- It is a rearrangement reaction. Hence, also known as Schmidt rearrangement reaction.
- This reaction is very closely related to another name reaction called Curtius rearrangement.
- When Schmidt reactions take place with carboxylic acid and ketone, hydrazoic acid is used, and nitrogen gets released.
- Schmidt reaction with carboxylic acid is shown below
Carboxylic acid + Hydrazoic acid → Primary amine + Carbon dioxide + Nitrogen
- The mechanism of this reaction is explained below
Step 1 – Formation of Acylium Ion
Schmidt reaction with carboxylic acid starts with the formation of acylium ions. It is formed by protonation of carboxylic acid with removal of water molecules.
Step 2 – Acylium ion reaction with Hydrazoic acid
Acylium ion reacts with hydrazoic acid and forms protonated azido ketone.
Step 3 – Rearrangement of Azido Ketone
Now azido ketone undergoes rearrangement with alkyl group (R) migrating over the C-N bond and with removal of nitrogen gas. Rearrangement of azido ketone forms protonated isocyanate.
Step 4 – Formation of Carbamate
Water molecules attack on the protonated isocyanate and form carbamate.
Step 5 – Deprotonation of Carbamate and formation of amine
Now carbamate undergoes deprotonation and forms carbon dioxide and amine.

Note:
In this reaction azide, a conjugate base of hydrazoic acid, reacts with a carbonyl derivative such as carboxylic acid, aldehyde, or ketone under acidic conditions to give amine or amides with release of nitrogen.