AROMATIC AMINO COMPOUNDS

Finar IL (2000) Organic chemistry, vol. 1 The fundamental principles, 6th edn, Chap. 23 Aromatic amino-compounds. Wiley, New York, p 664... 

The way in which aromatic amino compounds lead to the formation of MHb is of some interest in regard to the role played by the first reaction of the pentose phosphate cycle in this reaction system. It has been stated (L5) that nitrosobenzene effects within one hour the conversion of Hb to MHb to the extent of 80% of total pigment according to the following reactions ... 

Acetylation. Most mammalian species are able to acetylate aromatic amino compounds, the major exception being the dog. Thus, for a number of amino compounds such as procainamide (chap. 4, Fig. 43), sulfadimethoxine, sulfamethomidine, sulfasomizole, and the N4 amino group of sulfanilamide (chap. 4, Fig. 68), the dog does not excrete the acetylated product. However, the dog does have a high level of deacetylase in the liver and also seems to have an acetyltransferase inhibitor in the liver and kidney. Consequently, acetylation may not be absent in the dog, but rather the products may be hydrolyzed or the reaction effectively inhibited. 

Weiss, U. Edwards, J. M. The Biosynthesis of Aromatic Amino Compounds Wiley New York, 1980. 

The compounds are readily i>rcpared by boiling the sodium salt of chloracetylarsanilic acid with the aromatic amino-compound, the condensation occurring within fifteen to thirty minutes. The products... 

Coupling between aromatic amines and either phenols or other aromatic amino compounds is known and it is important in the production of azo polymers, and in the formation of azo dyes. Most of this work is outside the scope of this chapter a number of reviews are cited in ref. 20. One or two examples will suffice here to illustrate the area. Thus anthranilic acid (330) forms phenazine-l,6-dicaiboxylic acid (331) on treatment with manganese dioxide or lead dioxide in dry benzene or chloroform. The mechanistic details are obscure. Excellent yields could be obtained in intramolecular cases, e.g. amine (332)... 

In Britain during 1932-1933, a major discovery took place at what would soon be an ICI acquisition, Scottish Dyes. By chance, a blue colorant was obtained during preparation of phthalimide from phthalic anhydride and ammonia. Though not an aromatic amino compound, the stable product is important in the history of dye discovery. It was a phthalocyanine compound, of the type first prepared in 1907. ICI manufactured the copper analogue, known as Monastral fast blue. Introduced in 1934, it represented the first member of the only new structural class of synthetic dye in the 20th century83. 

When in 1925 the main German firms merged their interests to create the behemoth I.G. Farben, the name reflected historical roots rather than the main range of activity. Nevertheless, aromatic amino compounds were at the forefront of research into novel... 

Similar considerations apply to all aryl amine bladder carcinogens employed in the dye, rubber and leather industries51. Between 1930 and 1960, the toxic natures of many other coal-tar (aromatic) amino compounds, particularly azo dyes, were revealed52. 

Acetylation. Most mammalian species are able to acetylate aromatic amino compounds, the major exception being the dog. Thus, for a number of amino compounds such as procainamide (figure 4,42),... 

Datta, R. L. Varma, P. S. Replacement of sulfonic groups by nitro groups in aromatic amino compounds. Quart. J. Indian Chem. Soc. 1927, 4, 321-324. 

The water in some compounds that react with the Fischer reagent may be extracted with methanol of known water content. For non-volatile compounds that react and from which the water cannot be extracted in this way an azeotropic distillation method using either benzene or pyridine has been described by Roberts and Levin. Types of compounds likely to give rise to difficulties include those containing a reactive carbonyl group, phenolic and highly unsaturated substances, and reactive aromatic amino-compounds. 

Except for some polyfunctional aromatic amino-compounds (e.g. aminophenols, some amino-acids, phenylenediamines) aromatic amines are not soluble in water. Most dissolve in dilute hydrochloric acid, but some weak bases, e.g. nitroanilines, diphenylamines and polyhalogeno-anilines dissolve only in concentrated acids. A few aromatic amines (e.g. naphthylamines) dissolve in concentrated hydrochloric acid and then slowly precipitate as their sparingly soluble hydrochlorides. In all cases of doubt as to the solubility of a suspected amine in hydrochloric acid, a little of the filtered solution should be treated with an excess of alkali, when the amine (if insoluble in water) should be regenerated as an oil or solid. Amino-phenols and amino-acids are amphoteric substances (see pages 14-76). 

A carboamination reaction has been used for the construction of 1,4-benzodiazepines in good yield and diaster-eoselectivity. Wolfe et al. employed a substituted A-aryl aromatic amino compound as the precursor that after treatment with aryl bromide in the presence of the Pd catalyst, PPh2Cy ligand, and NaOt-Bu base under optimized conditions was transformed into substituted saturated benzodiazepine derivatives in good yield and diastereoselectivity (Scheme 40.17). °... 

Two chemical types generally used for pipeline repair arc epoxy and polyurethane (PU) resins. PUs have the advantage of curing at ambient temperatures via water activation, but the downside is that they are also easily hydrolysed in water and they have relatively low Tg values. In contrast, epoxy resins are more moisture stable and can be formulated to provide high Tg and environmental stability using aromatic amino compounds (Klein, 1991 Varma and Gupta, 2000). However, most thermosetting systems can only be applied on dry surfaces and are adversely affected by surface moisture and contaminants. Hence, ProAssure Wrap Extreme is a modified proprietary formulation that enhances adhesion in water environments. 

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