Aromatic amines 3-naphthylamine

Aromatic Amines /3-naphthylamine, phenyl-Q -naphthylamine, diphenylguanidine, phenthiazine [3] phenyl-)3-naphthylamine [35], N,N -diphenyl-p-phenylenediamine [56 ] N, N -di-/S -naphthyl-p-phenylenedi-amine [42, 44] N,N -phenylcyclohexyl-p-phenylenediamine [35, 42]. 

A) PRIMARY AROMATIC AMINES. RNH. Aniline, o-, m-, and p-toluidine (and other nuclear-substitiited anilines) 1- and 2-naphthylamines. (For note on Aliphatic Amines, cf. p. 375 )... 

The metal coordination complexes of both sahcylaldehyde phenyhiydrazone (91) and sahcylaldoxime provide antioxidant (92) protection and uv stabihty to polyolefins (see Antioxidants). In addition, the imines resulting from the reaction of sahcylaldehyde and aromatic amines, eg, p- am in oph en o1 or a-naphthylamine, can be used at very low levels as heat stabiLizers (qv) in polyolefins (93). 

Phloroglucinol is Hsted in the Colourindex as Cl Developer 19. It is particularly valuable in the dyeing of acetate fiber but also has been used as a coupler for azoic colors in viscose, Odon, cotton (qv), rayon, or nylon fibers, or in union fabrics containing these fibers (157). For example, cellulose acetate fabric is treated with an aromatic amine such as (9-dianisidine or a disperse dye such as A-hydroxyphenylazo-2-naphthylamine and the amine diazotizes on the fiber the fabric is then rinsed, freed of excess nitrite, and the azo color is developed in a phloroglucinol bath at pH 5—7. Depending on the diazo precursor used, intense blue to jet-black shades can be obtained with excellent light-, bleach-, and mbfastness. 

As with the parent aromatic hydrocarbons, diarylamiaes based oa polycyclic aromatic amines also tead to be more harmful. Thus, /V-phenyl-2-naphthylamine [135-88-6] (PBNA) metaboli2es ia the body to produce small amouats of 2-aaphthylamiae, a known carciaogea (37). ACGIH has desigaated PBNA to be an "iadustrial substance suspect of carciaogenic potential for man."... 

Bake sulfonation is an important variant of the normal sulfonation procedure. The reaction is restricted to aromatic amines, the sulfate salts of which ate prepared and heated (dry) at a temperature of approximately 200°C in vacuo. The sulfonic acid group migrates to the ortho or para positions of the amine to give a mixture of orthanilic acid [88-21-1] and sulfanilic acid [121 -57-3] respectively. This tendency is also apparent in polynuclear systems so that 1-naphthylamine gives 1-naphthy1amine-4-su1fonic acid. 

If relatively basic and nucleophilic aromatic amines are diazotized in nitrosylsul-furic acid, C- instead of TV-nitrosation takes place as shown by Blangey (1938) for 1-naphthylamine, which gave in this system 4-nitroso-l-naphthylamine. A possible mechanistic explanation of Blangey s observation is given in Section 3.2. 

Primary aromatic amines (e.g., aniline) and secondary aliphatic-aromatic amines (e. g., 7V-methylaniline) usually form triazenes in coupling reactions with benzenedi-azonium salts. If the nucleophilicity of the aryl residue is increased by addition of substituents or fused rings, as in 3-methylaniline and 1- and 2-naphthylamine, aminoazo formation takes place (C-coupling). However, the possibility has also been noted that in aminoazo formation the initial attack of the diazonium ion may still be at the amine N-atom, but the aN-complex might rearrange too rapidly to allow its identification (Beranek and Vecera, 1970). 

In a more recent paper (Stovpovoi et al., 1991b) Bagal and coworkers interpret their observation that Arrhenius plots of the rates of various N- and C-couplings of aromatic amines (e. g., 1-naphthylamine, 2,6-naphthylaminesulfonic acid, and 4-me-thylaniline) are linear only in aqueous systems, but not in aprotic solvents such as nitromethane or acetonitrile. Their explanation is based on an extension of the clas-... 

Note Other aromatic amines, e. g. 1- or 2-naphthylamine in acetic acid solution (Griess reagent), can be used as coupling agent instead of N-(l-naphthyl)-ethylenediamine ... 

Plasticiser/oil in rubber is usually determined by solvent extraction (ISO 1407) and FTIR identification [57] TGA can usually provide good quantifications of plasticiser contents. Antidegradants in rubber compounds may be determined by HS-GC-MS for volatile species (e.g. BHT, IPPD), but usually solvent extraction is required, followed by GC-MS, HPLC, UV or DP-MS analysis. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out. The determination of antioxidants in rubbers by means of HPLC and TLC has been reviewed [58], The TLC technique for antidegradants in rubbers is described in ASTM D 3156 and ISO 4645.2 (1984). Direct probe EIMS was also used to analyse antioxidants (hindered phenols and aromatic amines) in rubber extracts [59]. ISO 11089 (1997) deals with the determination of /V-phenyl-/9-naphthylamine and poly-2,2,4-trimethyl-1,2-dihydroquinoline (TMDQ) as well as other generic types of antiozonants such as IV-alkyl-AL-phenyl-p-phenylenediamines (e.g. IPPD and 6PPD) and A-aryl-AL-aryl-p-phenylenediamines (e.g. DPPD), by means of HPLC. 

Hydroperoxides oxidize aromatic amines more readily than analogous phenols. Thus, at 368 K cumyl hydroperoxide oxidizes a-naphthylamine and a-naphthol with ku = 1.4 x 10 4 and 1.7 x 10 5L mol-1 s 1, respectively [115,118], The oxidation of amines with hydroperoxides occurs apparently by chain mechanism, since the step of free radical generation proceeds much more slowly. This was proved in experiments on amines oxidation by cumyl hydroperoxide in the presence of /V,/V -diphcnyl-l, 4-phcnylcnediamine (QH2) as a radical acceptor [125]. The following reactions were supposed to occur in solution (80% decane and 20% chlorobenzene) ... 

The oxidation of primary and secondary alcohols in the presence of 1-naphthylamine, 2-naphthylamine, or phenyl-1-naphthylamine is characterized by the high values of the inhibition coefficient / > 10 [1-7], Alkylperoxyl, a-ketoperoxyl radicals, and (3-hydroxyperoxyl radicals, like the peroxyl radicals derived from tertiary alcohols, appeared to be incapable of reducing the aminyl radicals formed from aromatic amines. For example, when the oxidation of tert-butanol is inhibited by 1-naphthylamine, the coefficient /is equal to 2, which coincides with the value found in the inhibited oxidation of alkanes [3], However, the addition of hydrogen peroxide to the tert-butanol getting oxidized helps to perform the cyclic chain termination mechanism (1-naphthylamine as the inhibitor, T = 393 K, cumyl peroxide as initiator, p02 = 98 kPa [8]). This is due to the participation of the formed hydroperoxyl radical in the chain termination ... 

The synergistic action of a phenol and aromatic amine mixture on hydrocarbon oxidation was found by Karpukhina et al. [16]. A synergistic effect of binary mixtures of some phenols and aromatic amines in oxidizing hydrocarbon is related to the interaction of inhibitors and their radicals [16-26]. In the case of a combined addition of phenyl-A-2-naphthylamine and 2,6-bis(l,l-dimethylethyl)phenol to oxidizing ethylbenzene (v, = const, 343 K), the consumption of amine begins only after the phenol has been exhausted [16], in spite of the fact that peroxyl radicals interact with amine more rapidly than with phenol (7c7 (amine) = 1.3 x 105 and /c7 (phenol) = 1.3 x 104 L mol 1 s respectively 333 K). This phenomenon can be explained in terms of the fast equilibrium reaction [27-30] ... 

Historically, bladder tumors have been associated with exposures in the aniline dye industry. However, conclusive evidence for any one particular exposure could not be obtained in these studies since the workers were exposed to many chemicals within the same work area. For example, Case et al. (1954) investigated the incidence of bladder tumors among British workers in the chemical dye industry. In addition to aniline, the workers were exposed to other aromatic amines, including a- and P-naphthylamine, benzidine, and auramine. Although exposures could not be quantified, there was insufficient evidence to suggest that aniline was a cause of bladder cancers. More recent studies indicate that P-naphthylamine, 4-aminodiphenyl, 4-nitrodiphenyl, 4,4-diaminodiphenyl, or o-toluidine may be involved in increased cancers in the dye industry (Ward et al. 1991 Benya and Cornish 1994). 

Limit values for primary aromatic amines, aromatic aminosulfonic acids, certain cancerogenic amines (e.g., benzidine, 2-naphthylamine, 4-aminobiphenyl and 2-methyl-4-chloroaniline) and for polychlorinated biphenyls (PCB) should be viewed in the listed references of the specific country. 

Of the primary monoamines, some, such as. aniline, o-toluidine, xylidine, are colourless liquids. Others, such as p-toluidine, pseudo-cumidine and the naphthylamines, are solids. They can be distilled without decomposition and are volatile with steam. In water they are rather sparingly soluble—a 3 per cent solution of aniline can be made. The di- and polyamines are usually solids, not volatile in steam and much more soluble in water than the monoamines. The amines are basic in character, but, as a result of the negative nature of the phenyl-group, the aromatic amines are considerably weaker bases than are the aliphatic amines. Consequently aqueous solutions of the (stoicheio-metrically) neutral aniline salts are acid to litmus because of the hydrolysis which they undergo. For the same reason a small amount of the free base can be extracted with ether from an aqueous solution of an aniline salt. (Test with a solution of hydrogen chloride in ether or, after evaporation of the ether, by the reaction with bleaching powder.)... 

Dichloronitrobenzene has been prepared by deamination of 3,5-dichloro-4-nitroaniline and of 2,4-dichloro-3-nitroaniline. This procedure is an example of the rather general oxidation of anilines to nitrobenzenes with peroxytrifluoroacetic acid. Use of this reagent is frequently the method of choice for carrying out this transformation, and it is particularly suitable for oxidation of negatively substituted aromatic amines. Conversely, those aromatic amines, such as />-anisidine and j8-naphthylamine, whose aromatic nuclei are unusually sensitive to electrophilic attack give intractable mixtures with this reagent. This is not... 

Stern FB, Murthy LI, Beaumont JJ, et al Notification and risk assessment for bladder cancer of a cohort exposed to aromatic amines. III. Mortality among workers exposed to aromatic amines in the last 3-naphthylamine manufacturing facility in the United States. Occup Med27-.495-500, 1985... 

The main aromatic amines used as diazo components are substituted anilines or naphthylamines and the coupling components substituted iV-aUcylanilines, phenols, naphthylamines and naphthols. Heteroaromatic diazo and coupling components are widely used in commercial azo dyestuffs. The main heterocyclic conpling components are pyrazalones (2.6) and, especially, pyridones (2.8). These are nsed to prodnce bright yellow and orange monoazo dyes, such as Cl Acid Yellow 72 (2.7) and Cl Disperse Orange 139 (2.9). ... 

Ullmann and Fetvadjian reported the modification which made the synthesis more generally useful, when they heated together equimolar amounts of an aromatic amine and a phenol with paraformaldehyde or with benzaldehyde, thus making it possible to obtain unsymmetrical acridines (03CB1027). Thus, from 2-naphthol and 1-naphthylamine they obtained dibenzo[c,/]acridine (613), and from 2-naphthol and 2-naphthylamine dibenzo[c,fi]acridine (614). In a similar manner, from 1-aminoacridine and the two naph-thols are obtained the benzo [a]- and benzo[c]-naphtho[2,3-fi]acridines (615) and (616), and from 2-aminoacridine and the naphthols the benzo[a]- and benzo[c]-naphtho[2,3-/]acridines (617) and (618) (69JCS(C)1337). The isomeric benzofa]- and benzo[c]-... 

Secondary aromatic amines, such as phenyl beta-naphthylamine. have been used as antioxidants in elastomers, but the preferred antioxidants for plastics have been 2,6-disubstituted and 2,4,6-trisubstituted phenols. These hindered phenols serve as chain transfer agents with the macroradicals which are produced by the degradation of polymers. 

The high-temperature reaction of aromatic amines with aromatic nitro compounds in the presence of base affords primarily an azo compound [39,40]. Because two independent laboratories have reported reasonable results with this synthesis, the procedure is given here. To be noted is that, while the reaction as described here involves 2-naphthylamine, a known carcinogenic intermediate, it is given only for reference to the procedure. Evidently, other aromatic amines also undergo the reaction. 

Under similar conditions, secondary aromatic amines, such as JV-ethyl-1-naphthylamine, may also be nitrosated directly. 

Hydroperoxides oxidize aromatic amines more readily than analogous phenols. Thus, at 368 cumyl hydroperoxide oxidizes a-naphthylamine and a-naphthol with ku = 1.4 x 10 4... 

Thus, sulfate conjugation and acetylation may be involved in the metabolic activation of N-hydroxy aromatic amines, glutathione conjugation may be important in the nephrotoxicity of compounds, methylation in metal toxicity, glucuronidation in the carcinogenicity of p-naphthylamine and 3, 2 -dimethyl-4-aminobiphenyl. 

While aromatic amines in the ground state are good bases, the electron density at the amine nitrogen is drastically reduced in the first excited singlet state. On absorption of light an amine is therefore readily displaced from platinum(II). The complex dr-PtCl2( 1 -naphthylamine)2 is displaced with a quantum yield of 0.1 0.02 on irradiation at 280 or 313 nm in aqueous DMF (equation 315).947... 

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