The Schmidt reaction is an organic reaction involving alkyl migration over the carbon to nitrogen chemical bond in an azide with expulsion of nitrogen ^[1]. A key reagent introducing this azide group is hydrazoic acid and the reaction product depends on the type of reactant: carboxylic acids form amines through an isocyanate intermediate: Organic reactions are chemical reactions between organic compounds. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Atomic mass 14. ... A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... An azide is the N3- anion, the anion of hydrazoic acid or a reactive group in organic chemistry where a carbon substituent is attached as RN3. ... Hydrazoic acid is a colorless, volatile, and extremely explosive liquid at room temperature and pressure. ... Structure of a carboxylic acid The 3D structure of the carboxyl group A space-filling model of the carboxyl group Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula -C(=O)OH, usually written -COOH or -CO2H. [1] Carboxylic acids are Bronsted... The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... Isocyanate is the chemical group of atoms -N=C=O (1 nitrogen, 1 carbon, 1 oxygen), as opposed to cyanate, -O-C≡N, which is formed from cyanogen in the normal -ate manner. ...

and ketones form amides: Ketone group A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a chemical compound that contains this functional group. ... Amide functional group In chemistry, an amide is one of two kinds of compounds: - the organic functional group characterized by a carbonyl group (C=O) linked to a nitrogen atom (N), or a compound that contains this functional group (pictured to the right); or - a particular kind of nitrogen anion. ...

A catalyst is required which can be a protic acid usually sulfuric acid or a lewis acid. The reaction was discovered in 1924 by R.F. Schmidt ^[2] who successfully converted benzophenone and hydrazoic acid to benzanilide. It is a tool regularly used in organic chemistry for the synthesis of new organic compounds for example in that of the unusual 2-quinuclidone. It has been suggested that this article or section be merged into Catalysis. ... Sulfuric acid, H2SO4, is a strong mineral acid. ... In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ... Benzophenone, also known as diphenylmethanone, phenyl ketone, diphenyl ketone, or benzoylbenzene. ... Hydrazoic acid is a colorless, volatile, and extremely explosive liquid at room temperature and pressure. ... Organic chemistry is a specific discipline within chemistry which involves the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds consisting of primarily carbon and hydrogen, which may contain any number of other elements, including nitrogen, oxygen, halogens as well...

Reaction mechanism

The carboxylic acid Schmidt reaction starts with acylium ion 1 obtained from protonation and loss of water. Reaction with hydrazoic acid forms the protonated azido ketone 2 which goes through a rearrangement reaction with the alkyl group R migrating over the C-N bond with expulsion of nitrogen. The protonated isocyanate is attacked by water forming carbamate 4 which after deprotonation loses carbon dioxide to the amine. Protonation is the addition of a proton (H+) to an atom, molecule, or ion. ... Hydrazoic acid is a colorless, volatile, and extremely explosive liquid at room temperature and pressure. ... A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. ... Isocyanate is the chemical group of atoms -N=C=O (1 nitrogen, 1 carbon, 1 oxygen), as opposed to cyanate, -O-C≡N, which is formed from cyanogen in the normal -ate manner. ... Carbamates are a group of organic compounds sharing a common functional group with the general structure -NH(CO)O-. More precisely the carbamate group is considered an amide group with an alkoxy or hydroxy functional group next to the carbonyl group. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ...

The reaction is related to the Curtius rearrangement except that in this reaction the azide is protonated and hence with different intermediates. The Curtius rearrangement, as first defined by Theodor Curtius, is a chemical reaction that involves the rearrangement of an acyl azide to a isocyanate. ...

In the reaction mechanism for the ketone Schmidt reaction the carbonyl group is activated by protonation for nucleophilic addition by the azide forming intermediate 3 which loses water in a elimination reaction to temporary imine 4 over which one of the alkyl groups migrates from carbon to nitrogen with loss of nitrogen. A similar migration is found in the Beckmann rearrangement. Attack by water and proton loss converts 5 to 7 which is a tautomer of the final amide. In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. ... Ketone group A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a chemical compound that contains this functional group. ... In organic chemistry, a nucleophilic addition reaction is an addition reaction where in a chemical compound a pi bond is removed by the creation of two new covalent bonds by the addition of a nucleophile. ... An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism. ... An imine is a functional group or chemical compound containing a carbon-nitrogen double bond. ... In chemistry, the Beckmann rearrangement is the rearrangement of a ketoxime to the corresponding amide in concentrated sulfuric acid, phosphorus pentachloride or a few other catalysts. ... Tautomers are organic compounds that are interconvertible by a chemical reaction called tautomerization. ... Amide functional group In chemistry, an amide is one of two kinds of compounds: - the organic functional group characterized by a carbonyl group (C=O) linked to a nitrogen atom (N), or a compound that contains this functional group (pictured to the right); or - a particular kind of nitrogen anion. ...

Scope

An intramolecular Schmidt reaction has been applied to the synthesis of novel bicyclic lactams ^[3]: The structure of a bicyclic molecule contains two usually fused rings. ... A lactam (the noun is a portmanteau of the wods lactone + amide) is a cyclic amide. ...

External links

Schmidt reaction appearances in organic syntheses: Organic Syntheses is a scientific journal that Since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. ...

• Organic Syntheses, Coll. Vol. 10, p.207 (2004); Vol. 79, p.165 (2002). Link
• Organic Syntheses, Coll. Vol. 5, p.408 (1973); Vol. 44, p.41 (1964). Link

References