Mannich Reaction


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Mannich reaction

[′män·ikrē‚ak·shən]
(organic chemistry)
Condensation of a primary or secondary amine or ammonia (usually as the hydrochloride) with formaldehyde and a compound containing at least one reactive hydrogen atom, for example, acetophenone. Also known as Mannich condensation reaction.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Mannich Reaction

 

the substitution of hydrogen in organic compounds by an amino methyl group Mannich Reaction (amino methylation) upon action of formaldehyde and ammonia (as well as amines or their hydrochloride salts). Various compounds containing a mobile hydrogen atom at the carbon atom participate in the Mannich reaction—for example, aldehydes and ketones containing hydrogen at the a-carbon atom; malonic acid derivatives; phenols; heterocyclic compounds; and acetylene hydrocarbons. Equations representing the acetone and indol reactions are given below. Dimethylamine hydrochloride is used in the first case, and piperidine in the second:

The mechanism of the Mannich reaction apparently reduces to the formation of an amino methyl cation that attacks the carbon atom, which has a partially negative charge (electrophilic substitution):

The Mannich reaction is widely used in organic synthesis and in industry, mainly in the preparation of pharmaceuticals. The reaction was discovered in 1917 by the German chemist C. Mannich, who demonstrated its general nature and subsequently carried out studies on the reaction over a period of 30 years.

REFERENCE

Organicheskie reaktsii, collection 1. Moscow, 1948. Page 399. (Translated from English.)

B. L. DIATKIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The chemical attachment for PAR onto silica typically attained making use of Mannich reaction which involves silylation reaction with aminosilane flowed by amino methylation for PAR and aldehyde [21, 25].
With several functional groups such as carboxyl, methoxyl, and hydroxyl [16], lignin can be chemically modified by different methods like alkylation, hydroxymethylation, Mannich reaction, oxidation, and phenolation [17, 18].
1-Butyl-3methylimidazolium hydroxide ([bmim]OH) is a kind of basic functionalized ionic liquid and has been successfully used for Knoevenagel condensation reaction [7], Mannich reaction [8], Markovnikov addition reaction [9], Michael addition reaction [10,11], Feist-Benaryreaction [12], and cycloaddition reaction [13].
Tanfloc is obtained via Mannich reaction of the tannin extract with an amine and an aldehyde molecule (MANGRICH et al., 2014).
The company specializes in a wide range of organic reaction technologies such as Amination, condensation, hydrogenation; Amidation, dehydrogenation & Mannich Reaction; Alkylation, diazotization & nitration; Bromination, esterifiction & oxidation; Catalytic hydrogenation, etherification & reduction; Chlorination & hydrogenation.
According to the requirements of synthetic products in our research, the lignin needs to be modified by Mannich reaction [26, 27].
These include the formation of anionic polyacrylamide through hydrolysis, (17) the synthesis of sulfomethylated derivatives from the reaction of polyacrylamide with formaldehyde and sodium bisulfate, (18) the formation of aminomethylated polyacrylamide from the reaction of polyacrylamide with formaldehyde and dimethylamine (Mannich reaction), (19) and the generation of various derivatives by transamidation reactions including hydroxamated polyacrylamides used as a flocculant in the Bayer process.
A new compound of the amino ketone family can be synthesized through mannich reaction on 4-t-butyl cyclohexanone.
Mannich bases, beta-amino ketones carrying compounds, are the end products of Mannich reaction [1, 2].
Butcher, "Highly efficient one-pot, three-component Mannich reaction catalysed by boric acid and glycerol in water with major 'syn' diastereoselectivity," Tetrahedron Letters, vol.
Mannich bases are the end products of Mannich reaction with basic moiety of beta amino ketone [4, 5].