Lindgren oxidation
Encyclopedia
Lindgren oxidation named after Bengt O. Lindgren is a selective method for oxidizing aldehyde
s to carboxylic acid
s. It is often wrongly mentioned as Pinnick oxidation
.
The oxidation takes place in water containing solvent mixtures under slightly acidic conditions (pH 3–5) with sodium chlorite
as oxidizer. To avoide complicated oxidation reactions the hypochlorite
, which is formed in the reaction, has to be removed from the reaction mixture by scavengers. In the original publication sulfamic acid
and resorcinol
were used. George A. Kraus and co-workers were the first to use 2-methyl-2-butene as scavenger under buffered conditions for the oxidation of an aliphatic and an α,β-unsaturated aldehyde. While later hydrogen peroxide
also proved to work to remove the hypochlorite.
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
s to carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
s. It is often wrongly mentioned as Pinnick oxidation
Pinnick oxidation
The Pinnick oxidation is also known as Lindgren oxidation. It is an organic reaction by which aldehydes can be oxidized into its corresponding carboxylic acid, originally developed by Lindgren and Nilsson. The typical reaction condition used today was modified by G. A. Kraus even before Pinnick. ...
.
The oxidation takes place in water containing solvent mixtures under slightly acidic conditions (pH 3–5) with sodium chlorite
Sodium chlorite
Sodium chlorite is a chemical compound used in the manufacture of paper.-Use:The main application of sodium chlorite is the generation of chlorine dioxide for bleaching and stripping of textiles, pulp, and paper. It is also used for disinfection of a few municipal water treatment plants after...
as oxidizer. To avoide complicated oxidation reactions the hypochlorite
Hypochlorite
The hypochlorite ion, also known as chlorate anion is ClO−. A hypochlorite compound is a chemical compound containing this group, with chlorine in oxidation state +1.Hypochlorites are the salts of hypochlorous acid...
, which is formed in the reaction, has to be removed from the reaction mixture by scavengers. In the original publication sulfamic acid
Sulfamic acid
Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, and sulfamidic acid, is a molecular compound with the formula H3NSO3...
and resorcinol
Resorcinol
Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...
were used. George A. Kraus and co-workers were the first to use 2-methyl-2-butene as scavenger under buffered conditions for the oxidation of an aliphatic and an α,β-unsaturated aldehyde. While later hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
also proved to work to remove the hypochlorite.