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A second addition of amine leads to the displacement of 2,4-dinitroaniline (5) and formation of the König salt [5] (6a and 6b). The trans-cis-trans isomer of the König salt (6a) can react by either sigmatropic rearrangement or nucleophilic addition of a zwitterionic intermediate to give cyclized intermediate (7). [6] This has been suggested ...
The Eschweiler–Clarke reaction (also called the Eschweiler–Clarke methylation) is a chemical reaction whereby a primary (or secondary) amine is methylated using excess formic acid and formaldehyde. [1] [2] Reductive amination reactions such as this one will not produce quaternary ammonium salts, but instead will stop at the tertiary amine ...
The mechanism of the Mannich reaction starts with the formation of an iminium ion from the amine and formaldehyde. [4]: 140 The compound with the carbonyl functional group (in this case a ketone) will tautomerize to the enol form, after which it attacks the iminium ion.
The Delépine reaction is the organic synthesis of primary amines (4) by reaction of benzyl or alkyl halides (1) with hexamethylenetetramine (2) followed by acid hydrolysis of the quaternary ammonium salt (3). [1] [2] It is named after the French chemist Stéphane Marcel Delépine (1871–1965). Delepin reaction
Amine. In chemistry, amines (/ ə ˈ m iː n, ˈ æ m iː n /, [1] [2] UK also / ˈ eɪ m iː n / [3]) are compounds and functional groups that contain a basic nitrogen atom with a lone pair.Formally, amines are derivatives of ammonia (NH 3 (in which the bond angle between the nitrogen and hydrogen is 170°), wherein one or more hydrogen atoms have been replaced by a substituent such as an ...
The reaction mechanism of the Stevens rearrangement is one of the most controversial reaction mechanisms in organic chemistry. [4] Key in the reaction mechanism [5] [6] for the Stevens rearrangement (explained for the nitrogen reaction) is the formation of an ylide after deprotonation of the ammonium salt by a strong base.
But in 1909, K. Löffler and C. Freytag extended the transformation to simple secondary amines and applied the process in their elegant synthesis of nicotine (6) from N-bromo-N-methyl-4-(pyridin-3-yl)butan-1-amine (5). [8] [9] [10] The reaction mechanism only became clear around 1950, when S. Wawzonek investigated various N-haloamine cyclizations.
In this method, the sodium or potassium salt of phthalimide is N-alkylated with a primary alkyl halide to give the corresponding N-alkylphthalimide. [8] [9] [10] Upon workup by acidic hydrolysis the primary amine is liberated as the amine salt. [11] Alternatively the workup may be via the Ing–Manske procedure, involving reaction with hydrazine.