Amines anilines

If the molecular weight of the aniline is known, the number of amino groups can be calculated alternatively, if the aniline is known to be a monacidic base, its molecular weight can be calculated. If the molecular weight and the acidity of the aniline are both known, then dearly the method can be used to estimate the amount of aniline in a given sample. The method is general for many primary and secondary amines, aniline being used solely as a typical member of the former class. 

A special type of ammonio group is represented by 4-( 1 -pyridinium)-pyridine and other azinium analogs. Such products often result from self-quaternization of highly reactive derivatives. A -(4-Pyridyl)-and A -(3-nitro-4-pyridyl)-pyridinium chloride hydrochlorides (121) react with aniline, chloride ion, and water to give 4-substituted pyridines plus pyridine. l-(2-Quinolyl)- and l-(4-quinolyl)-pyridinium salts undergo 2- and 4-substitution, respectively, with amines, anilines, hydroxylamine, phenols, alkoxides, mercaptans, and chloride... 

One of the most important derivatives of benzene is nitrobenzene. The nitro group is —NOi. Nitrobenzene is important chiefly because it is readily converted into an aromatic amine, aniline, by reduction. One preparative procedure uses zinc as the reducing agent ... 

Primary aromatic amines (aniline, 3-toluidine, 4-anisidine and 3-chloroanilinc) react with 4 to give 2-[2-(arylamino)-l-cyanoviny]]benzimidazoles9 (see Houben-Weyl, Vol.E8c, p 314 with an experimental procedure).289... 

DNPh forms low mp additive compds with ammonia or amines (aniline, toluidine, naphthyl-amine, etc), which on intimate mixing with oxidants (AN, K nitrate, Na nitrate, K chlorate,... 

When aromatic compounds are reacted with hydrogen, the catalyst used determines which part of the molecule reacts. Thus, with the right catalyst, a nitro group can be converted to an amine without adding hydrogen to the ring. In this case the simplest aromatic amine (aniline) is produced. 

The first examples utilising A-heterocyclic carbenes as ligands in the Buchwald-Hartwig amination involved the in situ formation of the catalyst from the corresponding imidazolium salt and a Pd(0) source. Nolan reported IPr-HCl/PdjCdbalj as a catalytic system for the amination of aryl chlorides in excellent yields, using different types of amines, anilines, and also imines or indoles [142,143] (Scheme 6.46). Hartwig showed later that in some cases the reactions could be performed at room temperature and without anhydrous conditions even for aryl chlorides [ 144]. This was later shown for the less challenging bromides and iodides [145,146]. 

The first example of acid catalysis appeared in a 1934 patent in which it is claimed that surface catalysts, particularly hydrosilicates of large surface area , known at that time under the trade name Tonsil, Franconit, Granisol, etc. lead to a smooth addition of the olefine to the molecule of the primary aromatic amine . Aniline and cyclohexene were reacted over Tonsil at 230-240°C to give, inter alia, the hydroamination product, N-cyclohexylaniline [47]. 

Amines. Aniline Benzidine a-Naphthylamine p-Nitroaniline Dimethylaniline. 

In the previous analysis for the second quadrant amines, there was evidence that the presence of an aromatic ring (BzAM) increased competition with the deactivating intermediate(s) and significantly the amount of DHQ obtained. The study was thus extended to other aromatic amines aniline (AN), 2-ethylaniline (2-ETAN), 3-ethylaniline (3-ETAN) and N-ethylaniline (N-ETAN). These amines are not classified in the literature analysis of amine properties (16), although aniline and pyridine were studied by statistical analysis of their solvent properties and classified in the same sector (16). By analogy, we hypothesize that these model aromatic amines should be classified in the second sector. Thus, they may aid in an understanding of the specific role of the aromatic ring and the effect of an alkyl substituent. 

Aromatic amines are of considerable importance commercially. The simplest aromatic amine, aniline. ChH5NH2, is used in the production of various dyes and chemicals for color photography. 

As the anhydride of nitrous and perchloric acids, it is a very powerful oxidant. Pinene explodes sharply acetone and ethanol ignite, then explode ether evolves gas, then explodes after a few s delay. Small amounts of primary aromatic amines-aniline, toluidines, xylidines, mesidine-ignite on contact, while larger amounts exploded dangerously, probably owing to rapid formation of diazonium perchlorates. Urea ignites on stirring with the perchlorate, (probably for a similar reason). 

Organic bases. Any organic amine (aniline, triethylamine, etc.). As you use bases to work with acids, use a dilute acid (5 to 10% HC1, say) to extract or wash these bases. 

An early example of this strategy is the palladium black catalyzed conversion of (Z)-2-buten-l,4-diol with primary amines (cyclohexyl amine, 2-aminoethanol, -hexyl amine, aniline) at 120 °C to give A-substituted pyrroles in 46-93% yield [119]. Trost extended this animation to the synthesis of a series of AT-benzyl amines 169 from the readily available a-acetoxy-a-vinylketones 168 [120]. This methodology allowed for the facile preparation of pyrrolo-fused steroids. 

Because of the higher CH acidity (by 7-8 pKa units) of alkylidene malonates (441), as compared with that of dialkyl malonates (87JA809), one-pot syntheses of alkylidene aminomethylenemalonates (442) could be carried out readily with a wide variety of primary and secondary aliphatic and cycloaliphatic amines, anilines, naphthylamines and heterocyclic amines, trialkyl orthoformate, and alkylidene malonates (83MI1 86MI9). It was proposed that the higher CH acidity of alkylidene malonates was a consequence of the electrostatic (dipole-dipole) repulsion effects... 

The joint action of primary or secondary amines (aniline, allylamine, benzylamine, butylmethylamine, iV-mcthylglycine methyl ester etc.) and copper bis(acetylacetonate) on the thiophen ylide 258 leads to dimethyl aminomalonates 259 by a carbene insertion reaction294. 

Phenols (p-cresol, guaiacol, pyrogallol, catechol) and aromatic amines (aniline, p-tolidine, o-phenyldiamine, o-dianisidine) are typical substrates for peroxidases [90 -109]. These compounds are oxidized by hydrogen peroxide or hydroperoxides under peroxidase catalysis to generate radicals, which after diffusion from the active center of the enzyme react with further aromatic substrates to form dimeric, oligomeric or polymeric products. 

Amines aniline, cyclic amines, diethylamine, dimethylforamine, EDTA, propanediamine, -propylamine... 

Aromatic amines (anilines) may become activated in vivo to form reactive amines. These are nucleophiles and may attack DNA, forming covalent modifications. Aromatic nitro compounds can be metabolised to also form reactive amines. A-nitroso compounds result in the alkylation of oxygen sites in DNA bases (0-6 in guanine and 0-4 in thymidine) [8,10]. 

Fermenting yeast is able to reduce added nitrobenzene to the corresponding amine, aniline, to quite a considerable extent. Part of the added nitrobenzene remains unattacked, but 70% of it could be converted to aniline. Since a direct reduction of the nitro group to the amino group is improbable, Neuberg and Welde tried phytochemical treatment of the possible intermediaries, namely, nitrosobenzene and phenylhydroxylamine on the one hand and azoxybenzene and azobenzene on the other hand. 

Aromatic Amines (Anilines) The molecular ion peak (odd number) of an aromatic monoamine is intense. Loss of one of the amino H atoms of aniline... 

Some primary amines (aniline, toluidine) do not interfere, others (a-naphthylamine) do... 

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