Products of Amination

The homolytic amination by N-chloroamines is of great synthetic interest, with a selectivity and versatility comparable to those of the most selective electrophilic substitutions. The overall stoichiometry is shown by Eq. (1) 

Several factors contribute to the s mthetic success of this substitution. 

The amination of the anthraquinone dye 5 by N-chlorodimethylamine is a significant example of the versatility of this reaction also with complex molecules and of the exceptional substrate and positional selectivity. In fact 5 has 8 non equivalent free aromatic positions, but only the isomer 6 is formed in quantitative yield with complete conversion of 5 by using only a light excess of N-chloro-amine, and without formation of polysubstituted compounds [Eq. (2)]. 

The only exceptions, so far as orientation is concerned, Eire aJkylbenzenes, which are attacked with poor selectivity at the meta and para positions. 

The scope and the limitations of the general process will be illustrated by the behavior of the main classes of aromatic compounds. 

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Figure Bl.16.9. Background-free, pseudo-steady-state CIDNP spectra observed in the photoreaction of triethylamine with different sensitizers ((a), antliraquinone (b), xanthone, CIDNP net effect (c), xanthone, CIDNP multiplet effect, amplitudes multiplied by 1.75 relative to the centre trace) in acetonitrile-d3. The stmctiiral formulae of the most important products bearing polarizations (1, regenerated starting material 2, N,N-diethylvinylamine 3, combination product of amine and sensitizer) are given at the top R denotes the sensitizer moiety. The polarized resonances of these products are assigned in the spectra. Reprinted from [21].

Tannins may be found bound up with magnetite in waterside tube deposits. Degradation products of amines, glycols, polymeric dispersants, chelants, and other organics may also be found and usually are reported in the deposit analysis as a loss on ignition. 

The design of a general and efficient process for the hydroamination of alkenes would be a very important (economic) breakthrough for the production of amines. A... 

Hence, the copper surface catalyzes the following reactions (a) decomposition of hydroperoxide to free radicals, (b) generation of free radicals by dioxygen, (c) reaction of hydroperoxide with amine, and (d) heterogeneous reaction of dioxygen with amine with free radical formation. All these reactions occur homolytically [13]. The products of amines oxidation additionally retard the oxidation of hydrocarbons after induction period. The kinetic characteristics of these reactions (T-6, T = 398 K, [13]) are presented below. 

The improvements made in hydroaminomethylation technology suggest that certain variants of this reaction are sufficiently developed for the potential production of amines. The synthesis of linear tertiary and secondary amines from terminal alkenes shows promise in this regard. Belief s recent contributions towards hydroaminomethylation using ammonia to produce linear primary amines, which are of industrial significance due to their abundance, suggest a bright future for this reaction. Branched selective hydroaminomethylation remains relatively underdeveloped and needs further study. 

Urea ((NH2)2CO), a small and highly water soluble molecule, is an end product of amine and ammonia nitrogen metabolism and as such represents an example of biodetoxification (Section 6.4). The process is discussed in this section because it illustrates a genuine de novo biosynthetic pathway rather than detoxification involving chemical modification, via phase I and phase II reactions, of a pre-existing molecule as is the case for haem or steroid hormones. 

Another use of these reactions is in the production of amines, for example, the formation of aniline from benzene. The benzene is first nitrated in nitric acid, and then in another reactor the nitrobenzene is reduced to aniline with H2 (another use of Hz) in the reactions... 

Anderson et al. (1) prepared curable dental compositions consisting of the reaction products of amine-terminated polyethers, methacrylate-terminated polyethers, 2-hydroxyethyl(meth)-acrylate, and V-vinyl pyrrolidone. 

In the photocatalytic production of amines from alcohols and ammonia, the efFiciency varied with alcohol structure ethanol > methanol > 2-propanol > t-butanol. A hydrogen atmosphere enhanced the formation of amines, a process which was inhibited by oxygen ... 

The reaction serves for the production of amines from aldehydes or ketones through the oximes of these bodies. 

The advantage of the Hofmann degradation over other methods of producing amines is that other methods rely upon an Ss-2 mechanism. This prevents the production of amines on a tertiary carbon. The Hofmann degradation can produce amines with a primary, secondary, or tertiary alkyl position,... 

The formation of alkoxo intermediates may be occurring when monophosphines are used, but the stability of the amine complexes favors the deprotonation of coordinated amine. Instead, the alkoxo complexes may be important in catalytic systems involving chelating ligands [51]. Indeed, the DPPF complex [Pd(DPPF)(p-Bu C6H4)(0-f-Bu) reacted with diphenyl amine, aniline, or piperidine, as shown in Eq. (48), to give the product of amine arylation in high yields in each case [51]. Since, no alkali metal is present in this stoichiometric reaction, the palladium amide is formed by a mechanism that cannot involve external deprotonation by alkali metal base. 

Aminopyrazines are conveniently prepared from carboxamido-pyrazines by application of the Hofmann reaction (see Section V,B). Thus, Camerino and Palamidessi prepared aminopyrazine in 80% yield from carboxamidopyrazine.312 Aminopyrazine may also be prepared from the reaction of pyrazine with sodamide in liquid ammonia,313 and 3-amino-2,5-dimethylpyrazine is the product of amination of 2,5-dimethylpyrazine with sodamide in dimethyl-aniline.311 The ammonolysis of halopyrazines also represents a useful preparative procedure for aminopyrazines (see Section V,C). This reaction proceeds most easily in the case of fluoro compounds for example, fluoropyrazine is converted into aminopyrazine in 70% yield by treatment with concentrated aqueous ammonia at room temperature for 3 days,299 whereas the corresponding reaction with chloropyrazine has been carried out in a sealed tube at 150°.147 Alkaline hydrolysis of 2,4-dihydroxypteridines followed by decarboxylation yields aminopyrazines 315 thus, high-temperature alkaline hydrolysis of 7-methyl-2,4-dihydroxypteridine (7-methyIlumazine) gives, after decarboxylation of the intermediate pyrazinecarboxylic... 

The condensation products of amines and aldehydes have often been used as the reduc-tant. The most common commercial example is that arising from aniline and butyraldehyde for which the active ingredient has been identified as 3,5-diethyl-1,2-dihydro-l-phenyl-2-propyl-pyridine (DHP). A high purity grade, >85% active, has become available in recent years (Reilly Industries, PDHP Adhesive Accelerator Vanderbilt, Vanax 808 HP). 

Aromatic aUazines and ketazines. Polyphosphoric acid is an excellent catalyst and solvent for production of amines from aromatic aldehydes and ketones in the presence of various carbonyl reagents, for example, hydrazine, its salts, semicarbazide hydrochloride, toluene/i-sulfonohydrazide, and acid hydrazides. The reaction is usually complete at 100° within 15 min. The reaction is not useful in the case of aliphatic carbonyl compounds. 

Kenner and Knight point out that hydrazones are formed from free hydrazine bases, whereas hydrazine salts, such as phenylhydrazine acetate, yield osazones. It is emphasized that salt formation greatly favors such reactions as the production of amines from hydrazo compounds, a reaction which is represented as follows. The cation therefore... 

Treatment of an allene amine with a ruthenium catalyst, 10% of TiCl4 and methyl vinyl ketone to give a product of amine addition followed by Michael addition, a... 

The heading production of chemical products includes the conversion of allyl alcohol to glycerine with hydrogen peroxide, the production of epoxy-compounds such as epoxy soya oil (plasticizer for PVC) and organic peroxides (e.g. methyl-ethyl-ketone-peroxide, dibenzoylperoxide), which are used as free radical initiators in polymerization processes. The production of amine oxides such as lauryl-dimethyl-amine-oxide with hydrogen peroxide (used as a rinsing agent in dishwashers) is also included. 

Production of Amines Using Lipases the BASF process... 

FIGURE 19. Monoarylation products of amines with triphenylbismuthane... 

Polyrad [Aqualon]. TM for reaction products of Amine D and ethylene oxide. 

Perfluoromethylenecyclopropane is extremely reactive towards nucleophiles most alcohols, amines, and water undergo exothermal addition at 0°C with the exocyclic carbon acting as the electrophilic center.The reaction of water with perfluoromethylenecyclopropane gave 2,2,3,3-tetrafluorocyclopropanecarboxylic acid (5). The primary addition products of amines formed the respective amides 4 upon subsequent reaction with water. 

Besides the above CD processes, some of the recent novel applications of CD are outlined below. The production of amines from the hydrogenation of aniline and the selective production of diethanolamine from the reaction of monoethanolamine and ethylene oxide have been reviewed. A patent on the production of phenol from cumene hydroperoxide disclosed that solid acid catalysts such as zeolites, ion-exchange resins achieved 100% conversion with about 60 /o selectivity to phenol at 50-90°C and 0-10 psig. This process utilizes the heat of the decomposition of cumene hydroperoxide to effect the separation of the lower boiling components and hence reduces the energy cost and carbon dioxide emissions. 

Shell side corrosion is caused by decomposition of the bath. (The decomposition products of amines and glycols are corrosive.) Some decomposition and corrosion are inevitable however, excessive decomposition is usually due to overheating near the firetube. Corrosion inhibitors are commonly added. There are numerous reasons for overheating the bath localized ineffective heat transfer caused by fouling, excessive flame impingement, etc. An improper flame can sometimes be modified without system shutdown. Fouling, however, requires removal of the firetube. 

The three main divisions of this subject are nitration and the nitro compounds, the direct amination of petroleum hydrocarbons, and the direct cyanidation of hydrocarbons to nitriles. The production of amines by reduction of nitro compounds or by amination of chloro compounds are subsidiary interests which involve petroleum hydrocarbons only in the second step. It may be added that hydroxylamine itself and its salts are almost exclusively prepared from nitropropane and may be thus considered a petroleum chemical... 

Uracils can be prepared via reaction of primary amines with 3-ethoxyacryloyl isocyanate this method is particularly snitable for complex amines and has fonnd much use in recent years in the synthesis of, for example, carbocyclic nncleoside analogues as potential anti-viral agents. The immediate product of amine/isocyanate interaction can be cyclised under either acidic or basic conditions the method can also be applied to thionracil synthesis by the use of the corresponding isothiocyanate. 

More than 90 per cent of the ethylene dichloride is used caprively for the manufacture of vinyl chloride. The remainder forms part of the composition of antiknock additives or is used as an intermediate in the production of amines and chlorinated solvents. 

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