Schmidt Reaction

Schmidt Reaction is an organic chemical reaction. In this reaction, azides react with a compound's carbonyl group to form amides or amines. Karl Friedrich Schmidt first reported on this reaction in 1924.

Examples

The Schmidt Reaction can be utilized to yield amides by a reaction between an azide and a ketone. It can also produce amines by reacting an azide with carboxylic acid.

Carboxylic Acid Schmidt Reaction

The reaction that produces amines from an azide and a carboxylic acid is depicted below:

Schmidt's Ketone Reaction

Another example of the Schmidt Reaction is the formation of an amide from the reaction of an azide and a ketone. This reaction is depicted as below:

From hydrogen azide and benzophenone, the Schmidt reaction can be used to produce benzanilide. This is an example of how to make an amide from an azide and a ketone.

Mechanism of Reaction

The Schmidt reaction can be used to generate either amines or amides. A different functional group is required for each of these products (carboxylic acids and ketones respectively). As a result, the mechanisms for each of these reactions are described in detail below.

Mechanism for Amine Production

The emergence of an acylium ion from the protonation of the carboxylic acid is the initial step in this mechanism, followed by the water removal.
This acylium ion now reacts with hydrazoic acid, producing a protonated azido ketone.
The protonated R group and azido ketone are now subjected to a rearrangement reaction.
It results in the migration of the carbon-nitrogen bond and the removal of dinitrogen.
It results in the formation of a protonated isocyanate.
When water is introduced to react with the protonated isocyanate, a carbamate is formed.
Deprotonation of the carbamate now takes place.
The required amine is then obtained by removing the carbon dioxide

Mechanism for Amide Production

This mechanism starts with protonation of the ketone.
It results in the formation of an O-H bond.
An intermediate is formed as a result of the azide's subsequent nucleophilic addition.
Water is now removed from this intermediate by an elimination reaction.
It resulted in the formation of a temporary imine.
An alkyl group that was previously part of the ketone migrates from the carbon to the nitrogen of the imine.
As a result, dinitrogen gets eliminated.
Water is now used to rec with the resulting compound.
Deprotonation results in a tautomer of the required amide.
The final product i.e. amide is produced by the relocation of a proton from the amide's tautomer.

Frequently Asked Questions

Q1. Which isomers are formed during the rearrangement reaction?
A: The resulting products have the same molecular formula, but different structures or bonds between their atoms. Isobutane and butane, for example, have the same number of carbon (C) and hydrogen (H) atoms, so their chemical formulas are the same.

Q2. What medium does Favorskii rearrangement occur in?
A: The Favorskii rearrangement is a ring contraction in the case of cyclic -halo ketones. This rearrangement occurs in the presence of a base, occasionally hydroxide, to produce a carboxylic acid, but more often an alkoxide base or an amine to produce an amide or an ester, respectively.

Q3. Which reaction involves group migration from carbon to nitrogen?
A: The Schmidt reaction involves alkyl migration with nitrogen expulsion across the carbon-nitrogen chemical bond in an azide. The carboxylic acid Schmidt reaction begins with the acylium ion formed by water loss and protonation.

Q4. Explain reformatsky's reaction.
A: The Reformatsky reaction (also spelled Reformatskii reaction) is an organic reaction in which metallic zinc is used to form -hydroxy-esters. These are then used to condense ketones or aldehydes with al-halo esters. The organozinc reagent, also known as a Reformatsky enolate, is created by treating an alpha-halo ester with dust of zinc

Q5. What exactly is Schmidt rearrangement?
A: Schmidt reactions are hydrazoic acid reactions of electrophiles such as carbonyl compounds, alkenes, and tertiary alcohols, that are acid-catalyzed. These substrates, which include amines, amides, nitriles, and imines, go through nitrogen extrusion and rearrangement.