Solid aromatic amines

The reactions of solid diazonium salts with solid aromatic amines are less violent and the aryldiphenyltriazenium salts 311 or the 1,3-bis-aryltriazenium salts 313 and 315-HN03 are quantitatively obtained upon cautious cogrinding... 

Thiourea derivatives 164 were prepared by Kaupp et al. by mechanochemical reactions in which stoichiometric quantities of solid o-phenylene-di-isothiocyanate 161 reacts with the solid aromatic amines 162 in a ball-mill at room tanperature (Retsch MM2(X)0 miU with a lOmL stainless steel beaker and balls) [31]. The products, l-(aminoaryl-thiocarbonyl)-benzimidazolidine-2-thiones 163 were presumably... 

In general, benzoylation of aromatic amines finds less application than acetylation in preparative work, but the process is often employed for the identification and characterisation of aromatic amines (and also of hydroxy compounds). Benzoyl chloride (Section IV, 185) is the reagent commonly used. This reagent is so slowly hydrolysed by water that benzoylation can be carried out in an aqueous medium. In the Schotten-Baumann method of benzoylation the amino compound or its salt is dissolved or suspended in a slight excess of 8-15 per cent, sodium hydroxide solution, a small excess (about 10-15 per cent, more than the theoretical quantity) of benzoyl chloride is then added and the mixture vigorously shaken in a stoppered vessel (or else the mixture is stirred mechanically). Benzoylation proceeds smoothly and the sparingly soluble benzoyl derivative usually separates as a solid. The sodium hydroxide hydrolyses the excess of benzoyl chloride, yielding sodium benzoate and sodium chloride, which remain in solution ... 

The cure reaction of structural acrylic adhesives can be started by any of a great number of redox reactions. One commonly used redox couple is the reaction of benzoyl peroxide (BPO) with tertiary aromatic amines. Pure BPO is hazardous when dry [39]. It is susceptible to explosion from shock, friction or heat, and has an autoignition temperature of 79°C. Water is a very effective stabilizer for BPO, and so the initiator is often available as a paste or a moist solid [40], The... 

Our recent studies on effective bromination and oxidation using benzyltrimethylammonium tribromide (BTMA Br3), stable solid, are described. Those involve electrophilic bromination of aromatic compounds such as phenols, aromatic amines, aromatic ethers, acetanilides, arenes, and thiophene, a-bromination of arenes and acetophenones, and also bromo-addition to alkenes by the use of BTMA Br3. Furthermore, oxidation of alcohols, ethers, 1,4-benzenediols, hindered phenols, primary amines, hydrazo compounds, sulfides, and thiols, haloform reaction of methylketones, N-bromination of amides, Hofmann degradation of amides, and preparation of acylureas and carbamates by the use of BTMA Br3 are also presented. 

Nitroxyl radicals as alkyl radical acceptors are known to be very weak antioxidants due to the extremely fast addition of dioxygen to alkyl radicals (see Chapter 2). They retard the oxidation of solid polymers due to specific features of free radical reactions in the solid polymer matrix (see Chapter 19). However, the combination of two inhibitors, one is the peroxyl radical acceptor (phenol, aromatic amine) and another is the alkyl radical acceptor (nitroxyl radical) showed the synergistic action [44-46]. The results of testing the combination of nitroxyl radical (>NO ) (2,2,6,6-tetramethyl-4-benzoylpiperidine-l-oxyl) + amine (phenol) in the autoxidation of nonene-1 at 393 K are given here ([>NO ]o + [InH]o = 1.5 x 10 4mol L 1 p02 98 kPa) [44]. 

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.)... 

Anilines are converted into nitrosoarenes ArNO by the action of hydrogen peroxide in the presence of [Mo(0)(02)2(H20) (HMPA)]224, whereas catalysis of the reaction by titanium silicate and zeolites results in the formation of azoxybenzenes ArN (0)=NAr225. Azo compounds ArN=NAr are formed in 42-99% yields by the phase-transfer assisted potassium permanganate oxidation of primary aromatic amines in aqueous benzene containing a little tetrabutylammonium bromide226. The reaction of arylamines with chromyl chloride gives solid adducts which, on hydrolysis, yield mixtures of azo compounds, p-benzoquinone and p-benzoquinone anils 234227. 

We have mentioned above the prevalence of chromoisomeric effects in two-component systems forming solid charge-transfer complexes. This was studied first by Hertel (120) and labeled by him complex isomerism. In a system such as picric acid with an aromatic amine, there are a variety of structural possibilities. There will probably be intermolecular hydrogen bonds, which are associated with short lateral contacts between the near-planar molecules. In addition, there... 

Then, contrary to our previous hypothesis, the reaction proceeds via a Bai2 displacement of aniline on DMC. The product, mono-A -methyl aniline (PhNHMe), plausibly adsorbs into the zeohte in a different way with respect to anihne, because different H-bonds (N H — O-zeolite) take place with the solid. As recently reported by Su et al., A-methyl amines also may interact with NaY by H-bonding between the protons of the methyl group and the oxygen atoms of the zeolite this probably forces the molecule a bit far from the catalytic surface in a fashion less apt to meet DMC and react with it. This behavior can account for the mono-A-methyl selectivity observed, which is specific to the use of DMC in the presence of alkali metal exchanged faujasites in fact, the bis-A-methylation of primary aromatic amines occurs easily with conventional methylating agents (i.e., dimethyl sulfate). ... 

Brede, C., Skjevrak, I. and Herikstad, H. (2003). Determination of primary aromatic amines in water food simulant using solid-phase analytical derivatization followed by gas chromatography coupled with mass spectrometry, J. Chrom. A, 983, 35-42. 

Oostdyk TS, Grob RL, Snyder JL, et al. 1994. Solid phase extraction of primary aromatic amines from aqueous samples comparison with liquid-liquid extraction techniques. J Environ Sci Health... 

Azo couplings of diazonium salts with primary or secondary amines give triazenes which are normally hard to get in pure form. It is, however, quite easy to get triazenes with aliphatic or aromatic amines if solid-state techniques are applied that give rise to pure products in quantitative yield [98-100]. The di-methyltriazenes 309 have been quantitatively obtained by very cautious addition of gaseous dimethylamine (exothermic ) [98] (Scheme 47). Extreme care has to be taken for safety reasons ... 

Solid aromatic aldehydes (77a-e,j) react quantitatively with aliphatic amines (0.25 bar) at room temperature (77b at 0 °C) to give the solid AT-alkylazome-thines 322 and 323 without melting, which are dried at 80 °C in a vacuum. The yield is 100% throughout [12] (Scheme 50). 

A comparison of extraction methods for primary aromatic amines including 1,4-phenylenediamine, 2,4-diaminotoluene, benzidine, 4,4 -methylenebis (2-chloroanilme), 3,3 -dimethylbenzidine, and 3,3 -dichlorobenzidine from solid matrices was conducted. Supercritical fluid extraction (SEE) was evaluated and compared with the classical method, sonication extraction (Oost-dyk et al., 1993). 

The best human studies on chemicals and cancer manage to avoid the problems Feinstein described and also measure differences in cancer rates of greater than 1 percent (Lave and Ennever 1990). The most famous of those studies examined the relationship between cigarette consumption and cancer in British physicians (Doll and Hill 1964 Doll and Peto 1978). Researchers also have calculated solid dose-response relationships for coke-oven emissions, aromatic amines, aflatoxin, vinyl chloride, radiation (including radon), and asbestos (Zeise, Wilson, and Crouch 1987, 275-89). ... 

The related pentachlorophenyl derivative, [Tl(4,4 -bipy) Au(C6Cl5)2 ] 70, was obtained as an orange solid, either by reacting the polymeric precursor 31 with an equimolecular amount of 4,4 -bipyridine or from complex 67 and half an equivalent of the aromatic amine [68]. Its solid-state structure is completely different from that of... 

Fractional solidification and its applications to obtaining ultrapure chemical substances, has been treated in detail in Fractional Solidification by M.Zief and W.R.Wilcox eds, Edward Arnold Inc, London 1967, and Purification of Inorganic and Organic Materials by M.Zief, Marcel Dekker Inc, New York 1969. These monographs should be consulted for discussion of the basic principles of solid-liquid processes such as zone melting, progressive freezing and column crystallisation, laboratory apparatus and industrial scale equipment, and examples of applications. These include the removal of cyclohexane from benzene, and the purification of aromatic amines, dienes and naphthalene. 

In the U.S.S.R. photo-mass spectrometry has been used in a study of the photoionization and photodissociation of methylated benzene derivatives and the aromatic amines,16 and recently the hydrazine derivatives17 (Sec. III). Moreover, for many of the aromatic compounds the kinetic energy distribution of the photoelectrons has been measured in both the gaseous and the solid state (Secs. IV and V). 

Sulfonamides have usually been prepared on solid supports by sulfonylation of aliphatic or aromatic amines with sulfonyl chlorides or by N-alkylation of other sulfonamides (Figure 8.1). 

The 9-fluorenylmethoxycarbonyl group, developed by Carpino and co-workers in 1972 [257], has become one of the most widely used protective groups for aliphatic or aromatic amines in solid-phase synthesis. For solid-phase peptide synthesis in particular, this protective group plays an important role [258] (Section 16.1). The Fmoc group is not well suited for liquid-phase synthesis because non-volatile side products are formed during deprotection. 

Several stabilizers are useful in minimizing oxidative degradation during thermoplastic processing or in the bulk solid. Phenothiazine, hindered phenolic antioxidants such as butylated hydroxytoluene, butylated hydroxyanisole, and secondary aromatic amines in concentrations of 0.01—0.5% based... 

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