Acid dyes with ammonium salts

Para-rosaniline Chloride.—This carbinol is known as para-rosaniline, carbinol base. It is not a dye but when treated with acids it yields salts which are colored and which possess the properties of dyes. These salts result from one of the amino groups reacting with the acid, forming an ammonium salt, the tri-valent nitrogen of the amine becoming penta-valent in the salt, as in the formation of methyl ammonium chloride from methyl amine. 

Inositols, ie, hexaliydrobenzenehexols, are sugars that have received increasing study and are useful in the treatment of a wide variety of human disorders, including vascular disease, cancer, cirrhosis of the Hver, frostbite, and muscular dystrophy (269). Myoinositol esters prepared by reaction with lower fatty acid anhydrides are useful as Hver medicines and nonionic surfactants the aluminum and ammonium salts of inositol hexasulfate are useful anticancer agents (270). Tetraarjloxybenzoquinones are intermediates in the preparation of dioxazine dyes (266,271). The synthesis of hexakis(aryloxy)benzenes has also beenpubUshed (272). 

The starting materials of the aldehyde method may be sulfonated. For example. Cl Acid Blue 9 [2650-18-2] Cl Food Blue 2 (Cl 42090), is manufactured by condensing a-(A/-ethylanilino)-y -toluenesulfonic acid with o-sulfobenzaldehyde. The leuco base is oxidized with sodium dichromate to the dye, which is usually isolated as the ammonium salt. In this case, the removal of the excess amine is not necessary. However, this color caimot be used in the food sector because separation of the chromium compounds from the dye is difficult. An alternative method which gives food-grade Cl Acid Blue 9 (14) and dispenses with the use of sodium dichromate employs oxidative electrolysis of the leuco base (49). 

The 1 2 metal complex dyes are dyed either at neutral pH or with ammonium acetate, and the exhaustion achieved by the effect of van der Waals forces. The pH is then aUowed to go slightly acidic to form salt linkages between the dye anion and the protonated primary amine groups in the wool (NH3 ). AU the dyes have similar dyeing properties and the conditions of appHcation do not damage the wool. 

It is obtained by condensing benzaldehyde-o-sulfonic acid with 2 equivalents of N-ethylbenzylaniline, followed by sulfonation, oxidation, and conversion to the ammonium salt. The dissolved dye is then immersed in a dispersion of aluminum hydroxide and converted to the corresponding salt using aluminum chloride or barium chloride solution ... 

HNOs) aqua fortis. A corrosive liquid with a sharp odour that acts as a strong acid when dissolved in water. Nitric acid is used to synthesise ammonium nitrate for fertilisers, and is also used in the manufacture of explosives, dyes, and pharmaceuticals. Salts of nitric acid are called nitrates. 

Free formaldehyde is reacted with acetylacetone in the presence of an excess of an ammonium salt to form the yellow fluorescent compound, 3,5-diacetyl-1,4-dihydrolutidine and subsequently determined spectrophotometrically in methods A-E (14). In these methods, the test sample must be colorless and free from other carbonyl compounds. Some other derivatives have been used to analyze formaldehyde. For example, formaldehyde was reacted with sodium 4,5-dihydroxy-2,7-naphthalene disulfonate in sulfuric acid solution to yield a purple color (580 nm) and then subjected to colorimetric analysis. A purple-colored pararosaniline derivative was used to analyze formaldehyde in air (15). Air sample was passed through an aqueous solution which contained 0.4% of 3-methyl-2-benzothiazolone hydrazone hydrochloride and then a dye produced was determined at 635 or 670 nm (16). Molecular sieve (1.6 mm pettet) was used to trap formaldehyde in air samples. The formaldehyde... 

Normally, cotton is not dyeable after it has been cross-linked with A-methylolamide agents, such as DMDHEU. This is because the fibers are cross-linked in a collapsed state at elevated temperatures and they cannot swell adequately in aqueous solution to accommodate the relatively large dye molecules. However, cross-linked cotton is dyeable with anionic dyes under acidic pH conditions if reactive alkanolamines or hydroxyalkyl quaternary ammonium salts are incorporated in the finishing formulation. In addition, cotton cross linked with polycarboxylic acid, such as BTCA, or citric acid, is dyeable in similar fashion by using the same methods. Thus, these cross-linked cottons have affinity for acid, direct, and reactive anionic dyes at the pH range of 2.5-6.5, depending on the exact chemical composition of the substrate [561-564]. 

The acid forms glistening violet crystals, melting indefinitely about 265° C., giving violet solutions in ammonium hydroxide or 2N sodium carbonate, a reddish-violet solution in normal sodium hydroxide, a red solution in 2N sodium acetate, and a brownish-yellow solution in concentrated sulphuric acid. Magnesia mixture and ammonium hydroxide yield reddish-violet precipitates with the acid. When the acid is diazotised and coupled with R-salt, it gives a violet dye. Reduction with sodium hydrosulphite forms an orange-coloured vat, which imparts a violet stain to filter-paper. 

This colouring-matter formerly came into commerce in form of its ammonium salt as Palatine orange,and was used in paper-dyeing. It is formed by treating benzidine with nitrous acid, and boiling the resulting tetrazodiphenyl with nitric acid. 

The potassium salt of this acid, which is also known as picro-cyaminic acid, is obtained by treating picric acid with solution of potassium cyanide. The ammonium salt obtained from the potassium salt by double decomposition with ammonium chloride was formerly used in dyeing under the name Grenat soluble. It produces reddish-brown shades on wool and silk, but has now entirely disappeared. 

Chlorobenzene is employed in the synthesis of certain amino-containing vat dye intermediates. When reacted with phthalic anhydride, the product is 2-chloroanthraquinone, which, with ammonia, is converted readily into 2-aminoanthraquinone (61). Other routes include replacement of halogen by amino groups, with ammonia or ammonium salts of urea, and alkyl- and aryl amines to afford secondary amines. Modification of the amino group by alkylation, with dimethyl sulfate, alkyl halides or esters of toluenesul-fonic acids, is of synthetic value. Arylation of the amino groups is of importance only in the reaction between aminoanthraquinones and nitro- or chloroanthraquinones to yield dianthraquinonylamines, or anthrimides48. For example, the reaction between 62 and 63 yields 64, which can then be converted into carbazole 65, Cl Vat Brown R (Scheme 14). Amination of haloanthraquinones such as l-amino-4-bromoanthraquinone-2-sulfonic acid (bromamine acid) (66), prepared from 1-aminoanthraquinone, is of industrial use. 

The dynamics of mixtures of surfactants with proteins is of great importance for many practical processes, such as coating of photographic films, where gelatine in mixtures with surfactants and surface active dyes adsorb at the interface. Hempt et al. (1985) studied the relaxation behaviour of gelatine solutions in presence and absence of surfactants (SDS, tetradecyl dimethyl phosphine oxide, cetyltrimethyl ammonium bromide, n-decanoic acid, perfluoro octanoic acid tetraethyl ammonium salt). 

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