N-arylamine

A -Arylaziridines were synthesized in very good yield by palladium-catalyzed N-arylamination reactions utilizing BINAP or xantphos as suitable ligands and either CS2CO3 or NaO/-Bu as a base <07S243>. 

Methylation of arylamines. Reaction of ArNH, with paraformaldehyde, CHjONa, and CH3OH results in N-(methoxymethyl)-N-arylamines (2), which slowly decompose to form a triazinane via an imine, ArN=CH, (a). The imine can be reduced by NaBH4 in CH,OH to ArNHCH, (3) in high yield. 

Reacthity of chlorotropylium cations with nucleophiles. Alkuxy-, alkylthio-, and N-alkyl-N-arylaminotropylium. salts are prepared by reaction of chlorotropybum salts with alcohols, thiols, and N-alkyl-N-arylamines, respectively. With dimethylamine or with benzenesulfonamides chlorotropylium salts rearrange to yield bis(dimethyl-amino)phenylmethane or N-benzylidencsulfonamides. It is postulated that the formation of chlorocycloheptatrienes (IA, IB, 1C) is kinetically controlled, whereas substituted tropylium ions (3) are formed under thermodynamic control. 

Some examples of a benzidine-type of rearrangement are known for N-arylamines which, to some extent, may be considered as analogues of hydrazo compounds. Thus, 1-anilinoimidazole (279), on heating in concentrated hydroxhloric acid, is transformed to 4(5)-p-aminophenyl derivative (280) (70ZC289). 

N-Arylamines.Arylation of secondary amines in good regioselectivity is observed when the catalyst is supported on NaY zeolite. Such catalysts are easily separated after the reaction by filtration. 

Piperazines. Twofold (V-alkylation of N-arylamines with carbamates of bis(2-bromoethyl)amine on basic alumina at 150° forms N-arylpiperazines. The N-protecting group is also removed during the reaction. 

Direct incorporation of arylamino fragments into heteroaromatic compounds has some features. Unfortunately, the oxidative amination and alkylami-nation procedures cannot be applied for arylamination, because of a reduced A-nucleophilic character, a high sensitivity of aromatic amines towards oxidation, and a low stability of arylamino-arylamination reactions are still rare. A vast majority of the known examples are intramolecular reactions, which are performed in the presence of mild oxidants, such as sulfur, chloranU, or nitrobenzene (for review, see [34]). In some cases, air oxidation of the intermediate 7 -complexes has been observed. In the series of nitroarenes the nitro group often acts as the hydride ion acceptor. Similarly, in arylamination of azaaromatics the cyclic C=N bmid can intercept the hydride ion. 

N-Alkyl-N-arylcarbamoyl chlorides have been synthesized in >90% yield by the carbamoylation of secondary N-alkyl-N-arylamines with triphosgene for 2-3 h at 0-23 °C in a solvent (benzene, toluene, xylene, or chloroform), and in the presence of an organic base (triethylamine, N,N-diisopropyl-N-ethylamine, or pyridine) [123]. 

Although, generally, production of aminobenzene (aniline) and related N-arylamines by nitration and subsequent reduction is so common as to far outweigh other methods of formation of such compounds, special circumstances (such as a need to avoid the acidic conditions normally associated with nitronium ion [N02" ] formation) occasionally prevail and alternative methods need to be used. 

Aryl and alkenyl phenyl sulfides are prepared by the reaction of aryl and alkenyl halides and inflates with tributylstannyl phenyl sulfide. 2-Chloropyrimidine (737) is used for the coupling[606,607]. The diaryl or divinyl sulfide 739 is prepared by the reaction of distannyl sulfide (738)[548], N,N-Diethylaminotributyltin (740) reacts with aryl halides to give arylamines[608]. 

Arylamines Aniline like alkylamines has a pyramidal arrangement of bonds around nitrogen but its pyramid is somewhat shallower One measure of the extent of this flat tenmg is given by the angle between the carbon-nitrogen bond and the bisector of the H—N—H angle... 

We learned m the preceding section that different reactions are observed when the var lous classes of alkylammes—primary secondary and tertiary—react with mtrosatmg agents Although no useful chemistry attends the nitrosation of tertiary alkylammes elec trophilic aromatic substitution by mtrosyl cation ( N=0 ) takes place with A A dialkyl arylamines... 

A reaction of aryl diazonium salts that does not involve loss of nitrogen takes place when they react with phenols and arylamines Aryl diazonium ions are relatively weak elec trophiles but have sufficient reactivity to attack strongly activated aromatic rings The reaction is known as azo coupling two aryl groups are joined together by an azo (—N=N—) function... 

Electrophilic aromatic substitution (Sec tion 22 14) Arylamines are very reac tive toward electrophilic aromatic sub stitution It IS customary to protect arylamines as their N acyl derivatives before carrying out ring nitration chio rination bromination sulfonation or Friedel-Crafts reactions... 

Secondary alkylamines and secondary arylamines y e d N nitroso amines... 

BenZotrichloride Method. The central carbon atom of the dye is supphed by the trichloromethyl group from iJ-chlorobenzotrichloride. Both symmetrical and unsymmetrical triphenyhnethane dyes suitable for acryhc fibers are prepared by this method. 4-Chlorobenzotrichloride is condensed with excess chlorobenzene in the presence of a Lewis acid such as aluminium chloride to produce the intermediate aluminium chloride complex of 4,4, 4"-trichlorotriphenylmethyl chloride (18). Stepwise nucleophihc substitution of the chlorine atoms of this intermediate is achieved by successive reactions with different arylamines to give both symmetrical (51) and unsymmetrical dyes (52), eg, N-(2-chlorophenyl)-4-[(4-chlorophenyl) [4-[(3-methylphenyl)imino]-2,5-cyclohexadien-l-yhdene]methyl]benzenaminemonohydrochloride [85356-86-1J (19) from. w-toluidine and o-chloroaniline. 

Zirconium dichiorohis(dimethylamide) [87227-57-4] ZrCl2[N(CH2)2]2 h made direcdy from methylamine and zirconium tetrachloride but all of the halogens can be substituted by treating zirconium tetrachloride with the appropriate lithium alkylamide (229). Zirconium arylamines are made from zirconium alkoxides which first are converted to aryloxides (230). 

The submitters have found that other arylamines may be employed in a similar manner in place of aniline. Thus N-2-cyanoethyl-/)-anisidine was obtained in 76% yield as plates,... 

Arenediazonium salts undergo a coupling reaction with activated aromatic rings such as phenols and arylamines to yield brightly colored azo compounds, Ar—N=N—Ar. ... 

This reaction has been shown100 to be involved in the degradation in vivo of carcinogenic arylamines by N-hydroxylation and subsequent rearrangement. 

The treatment of acyl halides with ammonia or amines is a very general reaction for the preparation of amides.The reaction is highly exothermic and must be carefully controlled, usually by cooling or dilution. Ammonia gives unsubstituted amides, primary amines give A-substituted amides, and secondary amines give N,N-disubstituted amides. Arylamines can be similarly acylated. In some cases aqueous... 

Artificial sweeteners see Sweetening agents Artisil blue 2RP 129 Arylamines 66,151, 294 N-Aryl-N -benzenesulfonylthiocarbamides 248, 249... 

Aromatic azo compounds, many of which are sulfonated, are components of many commercially important dyes, colorants, and pigments, so that attention has been directed to their degradation and transformation. These compounds are often considered recalcitrant, although then-transformation has been accomplished by reduction to amines with scission of the Ar-N=N-Ar bond to produce arylamines. The amines may then be degraded, for example, 6-aminonaphthalene-2-sulfonate by dioxygenation and ring fission to 5-aminosalicylate (Hang et al. 1991). This is then... 

Bertrand T, Jolivalt C, Briozzo P, Caminade E, Joly N, Madzak C, Mougin C. 2002. Crystal structure of a four-copper laccase complexed with an arylamine Insights into substrate recognition and correlation with kinetics. Biochemistry 41 7325-7333. 

The classic syntheses of the antibacterial sulfonamides involve reaction of the appropriate arylamine with an acid addition salt of p-amino-benzenesulfonyl chloride, or p-nitrobenzenesulfonyl chloride followed by reduction. Chemical interest largely resides in preparation of the corresponding arylamines. For the synthesis of sulfacytine (134), N-ethyl uracil (131) was converted to its thioamide (132) by reaction with phosphorous pentasulfide. The newly introduced sulfur is then displaced with ammonia in methanol to give 133. Standard reactions complete... 

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