Schmidt Reaction: Overview, Questions, Preparation

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Nitro Compounds Diazonium Salts Schmidt Reaction

Updated on Jun 28, 2021 01:02 IST

The Claisen-Schmidt condensation is called the reaction between an aldehyde or ketone containing an al-hydrogen and an aromatic carbonyl compound without an al-hydrogen. In the absence of solvent using sodium hydroxide as the base and plus benzaldehydes, quantitative yields in Claisen–Schmidt reactions have been recorded.

Table of content

Schmidt Reaction Process
Illustrated Examples
FAQs on Schmidt's reaction

Schmidt Reaction Process

Mechanism with Carboxylic Acids	Mechanism with reaction with Ketones
Acylium Ion Formation - The Schmidt carboxylic acid reaction begins with the formation of an acylium ion. It is made up of Carboxylic acid protonation with water molecule elimination.	Activation of the Carbonyl Ketone Group - The carbonyl ketone group is activated by azide protonation for nucleophilic addition.
Acylium Ion Hydrazoic Acid Reaction - Acylium ion reacts with hydrazoic acid and forms azido ketone with protonation.	Azidohydrin formation - Azidohydrin is formed by nucleophilic attachment of nucleophilic N to the activated carbon of the ketone carbonyl community.
Azido Ketone Rearrangement - Azido ketone is now being rearranged with the alkyl group (R) migrating over the C-N bond and eliminating nitrogen gas. Azido ketone rearrangement forms protonated isocyanate.	Diazoiminium Formation - Azidohydrin loses water molecules to give diazonium in an elimination reaction.
Carbamate formation - The water molecule targets and forms carbamate on the protonated isocyanate. Carbamate Deprotonation and Amine Formation Carbamate is now being deprotonated and forms carbon dioxide and amine.	Nitrilium Intermediate Formation - As in the Beckmann rearrangement, one of the alkyl (or aryl) groups migrate from diazonium carbon to nitrogen with nitrogen loss to give intermediate nitrilium.
	Imidic Acid Formation - A water molecule now targets and converts nitrilium intermediate into protonated imidic acid.
	Shape of Amide - To achieve the tautomer of the final amide, imidic acid now undergoes proton depletion.

Schmidt Reaction in Class 12:

Under the amine chapter, the Schmidt reaction is present, and you will get to learn its mechanism and how it took place; and also, there are 2-3 examples present. The chapter is a part of organic chemistry, which has a weightage of 28 marks.

Illustrated Examples

What explains Reformatsky's reaction?

Reformatsky reaction is an organic reaction that uses metallic zinc to condense aldehydes/ketones with alpha-halo esters to make β-hydroxy-esters. The organozinc reagent, also known as 'Reformatsky enolate', is made by treating an alpha-halo ester with dust of zinc.

In which medium is Favorskii rearranged?

The Favorskii rearrangement represents a ring contraction in the case of cyclic al-halo ketones. This rearrangement takes place to create a carboxylic acid in the presence of a base, often hydroxide, but much of the time either an alkoxide base or an amine to produce an ester or an amide, respectively.

In a Schmidt rearrangement, which reagent is used?

Hydrogen azide acid-catalyzed reaction with electrophiles, such as carbonyl compounds, tertiary alcohols, or alkenes.

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FAQs on Schmidt's reaction

Q. In Schmidt's reaction, what is the reagent?

A. Hydrazoic acid is a crucial reagent that incorporates this azide group, and the reaction product(s) depends on the substrate's existence.

Q. What is the rearrangement of Schmidt?

A. Schmidt reactions refer to acid-catalyzed hydrazoic acid reactions of electrophiles, such as tertiary alcohols, carbonyl compounds, and alkenes. To provide amines, nitriles, amides, or imines, these substrates undergo rearrangement and extrusion of nitrogen.

Q. What is the Schmidt Claisen Reaction?

A. Claisen-Schmidt condensation is the response to an aldehyde or ketone having an alpha-hydrogen with an aromatic carbonyl compound without alpha hydrogen.

Q. In the rearrangement reaction, what kind of isomers are formed?

A. Butane and isobutane have an equal number of carbon (C) atoms and hydrogen (H) atoms, so their chemical formulas are identical.

Q. Migration of groups from carbon to nitrogen happens in which reaction?

A. The above reaction is called the Schmidt reaction, which entails alkyl migration with nitrogen expulsion over the chemical bond of carbon-nitrogen in an azide. The Schmidt reaction of carboxylic acid begins with the acylium ion derived from protonation and water loss.