Naphthylamines, and the

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. 

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). ... 

The N—H 7i hydrogen bonding interaction was studied by uv spectrophotometry of the system 1-naphthylamine and the donors reported in Table 2126. The equilibrium constant increases by increasing the number of electron donor substituents on the n donor partner. This behaviour parallels that observed extensively for O—H n interaction between phenols, or alcohols with alkenes or aromatic hydrocarbons127. 

Flett [32] has found similar effects with amino-anthraquinones and he has shown that in these structures hydrogen bonding can play only a small part, even with unsubstituted amines. Thus the NH stretching frequency of 1-amino-anthraquinone is not very different from that of 2-naphthylamine, and the NH frequency of 1-methyl-amino-anthraquinone is only 100 cm" lower than is usual for secondary amines. This contrasts sharply with the behaviour of the corresponding hydroxy-compounds, in which no OH stretching frequencies are shown in the normal frequency range. Furthermore, Flett finds that 2-amino-anthraquinones show nearly as much movement of the carbonyl absorption as the 1-amino-materials, and... 

Bucherer reaction Bucherer discovered that the interconversion of 2-naphthol and 2-naphthylamine through the action of alkali and ammonia could be facilitated if the reaction was carried out in the presence of (HSO3]" at about 150 C. This reaction is exceptional for the ease with which an aromatic C —OH bond is broken. It is not of general application, it is probable that the reaction depends upon the addition of [HSO3]" to the normally unstable keto-form of 2-naphthol, and subsequent displacement of —OH by —NH2. 

Physical properties. Majority are liquids except p toluidine and 1- and 2-naphthylamine. All are colourless when pure, but rapidly darken on exposure to air and light. All are very sparingly soluble in water, but dissolve readily in dilute mineral acids (except the naphthyl-amines, which are only moderately soluble in adds). They form colourless crystalline salts e.g., CjHjNH2,HCl) which are soluble in water these aqueous solutions usually have an add reaction owing to hydrolysis, and give the reactions of both the amine and the acid from which they are derived. Addition of alkali to the acid solution liberates the amine. 

Some amines, such as the nitroanilines and the naphthylamines, give somewhat more stable diazonium compounds and may be diazotised at room temperature, when the reaction proceeds more rapidly. If the amine salt is only sparingly soluble in water, it should be suspended in the acid in a fine state of division (this is generally attained by cooling a hot solution and stirring vigorously), and it passes into solution as the soluble diazonium salt is formed. 

Fluoronaphthalene [323-09-1] is prepared in 54—67% yield from 2-naphthylamine by the Balz-Schiemann reaction or in 51% yield by pyrolysis of indene and chlorofluoromethane at 600°C (77). 

Naphthaleneamine. 1-Naphthylamine or a-naphth5iamine/7i5 -i2- can be made from 1-nitronaphthalene by reduction with iron—dilute HCl, or by catalytic hydrogenation it is purified by distillation and the content of 2-naphthylamine can be reduced as low as 8—10 ppm. Electroreduction of 1-nitronaphthalene to 1-naphthylamine using titania—titanium composite electrode has been described (43). Photoinduced reduction of 1-nitronaphthalene on semiconductor (eg, anatase) particles produces 1-naphthylamine in 77% yield (44). 1-Naphthylamine/7J4-J2-. can also be prepared by treating 1-naphthol with NH in the presence of a catalyst at elevated temperature. The sanitary working conditions are improved by gas-phase reaction at... 

In the ketone method, the central carbon atom is derived from phosgene (qv). A diarylketone is prepared from phosgene and a tertiary arylamine and then condenses with another mole of a tertiary arylamine (same or different) in the presence of phosphoms oxychloride or zinc chloride. The dye is produced directly without an oxidation step. Thus, ethyl violet [2390-59-2] Cl Basic Violet 4 (15), is prepared from 4,4 -bis(diethylamino)benzophenone with diethylaruline in the presence of phosphoms oxychloride. This reaction is very useful for the preparation of unsymmetrical dyes. Condensation of 4,4 -bis(dimethylamino)benzophenone [90-94-8] (Michler s ketone) with AJ-phenjl-l-naphthylamine gives the Victoria Blue B [2580-56-5] Cl Basic Blue 26, which is used for coloring paper and producing ballpoint pen pastes and inks. 

All the evidence suggests that such groups always exist in the amino form, and the reactions and behavior of these compounds resemble those of aniline and the naphthylamines. For example, the amino form of 7-aminophenazin-2-ones (246) would be expected to be more stable than the imino form (247), and their weak basicity supports this expectation. ... 

Acyl-3.4-benzo-2-azabicyclo[3.2.0]hepta-3,6-dienes 1, on heating at 250-280 C for a short time without solvent, rearrange to the 1-acyl-1-benzazepines 2 (Method A).23-38 In some cases, rearrangement is accompanied by minor amounts of Ar-aeyl-l-naphthylamine and, at higher temperatures, the acylnaphthylatnine can become the major product (see Section 3.2.2.6.). In the presence of silver(I) tetrafluoroborate (Method B) rearrangement takes place at lower temperatures but the yields of benzazepine are inferior as the silver(I) ion also catalyzes the reverse reaction (see Section 3.2.2.1.). 

For substituted anilines (Thompson and Williams, 1977) and for 1-naphthylamine and a series of derivatives thereof (Castro et al., 1986a), k2 and the ratio Ar 2/Ar3 have been determined for nucleophilic catalysis with Cl-, Br-, SCN-, and SC(NH2)2. The values of k2 correspond fairly well to those found for the diazotization of aniline, but those of Ar 2/Ar3 increase markedly in the above sequence (Table 3-1). As k3 is expected to be independent of the presence of Cl- or Br- and to show little dependence on that of SCN- or thiourea, the increase in k 2/k3 for this series must be due mainly to 2. Indeed, the value of log(Ar 2/Ar3) shows a linear correlation with Pearson s nucleophilicity parameter n (Pearson et al., 1968). This parameter is based on nucleophilic substitution of iodine (as I-) in methyl iodide by various nucleophiles. The three investigations on nucleophilic catalysis of diazotization demonstrate that Pearson s criteria for bimolecular nucleophilic substitution at sp3 carbon atoms are also applicable to substitution at nitrogen atoms. 

If the coupling component is not ionic, however, more dramatic effects occur, as found by Hashida et al. (1979) and by Tentorio et al. (1985). Hashida used N,N-bis(2-hydroxyethyl)aniline, while Tentorio and coworkers took 1-naphthylamine and l-amino-2-methylnaphthalene as coupling components. With cationic arenediazo-nium salts and addition of sodium dodecyl sulfate (SDS), rate increases up to 1100-fold were measured in cases where the surfactant concentration was higher than the critical micelle concentration (cmc). Under the same conditions the reaction... 

A kinetic study of the desulphonation of 2-naphthylamine-l-sulphonic acid by hydrochloric, sulphuric and phosphoric acids showed the rate to be proportional to the concentration of hydrogen ions and the aromatic and a mechanism involving the formation of 1-naphthylsulphamic acid was proposed702. 

The scope and mechanism of the isomerization of arylamines to methyl-substituted aromatic heterocycles have been studied. Aniline, toluidines, naphthylamines and m-phenylenediamine all gave the corresponding ortho-methyl-substituted aza-aromatics when exposed to high NHj pressure and elevated temperature in the presence of acid catalysts, e.g., zeolites. The yiel of pyridines formed by this process range from low to moderate <95JC(155)268>. 

Substituted amides suffer hydrolysis with greater difficulty. The choice of an acid or an alkaline medium vill depend upon (a) the solubility of the compound in the medium and (b) the effect of the reagent upon the products of hydrolysis. Substituted amides of comparatively low molecular weight (e.g., acetanilide) may be hydrolysed by boiling either with 10 per cent, sodium hydroxide solution or with 10 per cent, sulphuric acid for 2-3 hours. Other substituted amides are so insoluble in water that little reaction occurs when they are refluxed with dilute acid or dilute alkali for several hours. These include such substances as benzanilide (C(H(CONHC,Hg) and the benzoyl derivative of a naphthylamine (C.HjCONHCioH,) or a toluidine (C gCONHCjH,). For these substances satisfactory results may be obtained with 70 per cent, sulphuric acid this hydrolysis medium is a much better solvent for the substituted amide than is water or more dilute acid it also permits a higher reaction temperature (compare Section IV 192) ... 

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. 

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