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1.4- Dihydroxyanthraquinone quinizarin

The first group includes 1,2-dihydroxyanthraquinone, commonly known as alizarin, 1,4-dihydroxyanthraquinone (quinizarin), and 1,2,4-trihydroxyan-thraquinone (purpurin). Alizarin in particular has been known and appreciated for thousands of years in the form of its lake , i.e., the coordination complex of 1,2-hydroxyanthraquinone 88 with aluminum and calcium (Madder Lake, Turkey Red). [Pg.510]

Production of 1,4-dihydroxyanthraquinone (quinizarin) is a particularly important example. It is obtained by the reaction of phthalic anhydride with p-chloro-phenol at 170 to 190 °C. [Pg.354]

The synthesis of the hrst of these agents starts with the dye intermediate leucoquinizarin (35-1), the reduction product of the dihydroxyanthraquinone, quinizarin. Condensation with A-(2-hydroxyethyl)ethylenediamine (35-2) leads to the corresponding bis imine (35-3). Air oxidation may be visualized as starting at the hydroquinone-like central ring bond reorganization will lead to ametrantrone (35-4) [35]. [Pg.113]

Materials. Beside inorganic materials (eg, barium chloride/fluoride crystals, doped with 0.05% samarium), transparent thermoplasts are preferred for the PHB technique, eg, poly (methyl methacrylate) (PMAIA), polycarbonate, and polybutyral doped with small amounts of suitable organic dyes, organic pigments like phthalocyanines, 9-arninoacridine, 1,4-dihydroxyanthraquinone [81-64-1] (quinizarin) (1), and 2,3-dihydroporphyrin (chlorin) (2). [Pg.155]

Dihydroxyanthraquinone. This anthraquinone, also known as quinizarin [81-64-1] (29), is of great importance in manufacturing disperse, acid, and vat dyes. It is manufactured by condensation of phthalic anhydride (27) with 4-chlorophenol [106-48-9] (28) in oleum in the presence of boric acid or boron trifluoride (40,41). Improved processes for reducing waste acid have been reported (42), and yield is around 80% on the basis of 4-chlorophenol. [Pg.311]

Although anthraquinone is the starting point for the preparation of many derivatives, involving substitution and replacement reactions, certain compounds are obtained directly by varying the components in the above synthesis. Thus, for example, replacement of benzene with methylbenzene (toluene) leads to the formation of 2-methylanthraquinone. A particularly important variation on the phthalic anhydride route is the synthesis of 1,4-dihydroxyanthraquinone (6.6 quinizarin) using 4-chlorophenol with sulphuric acid and boric acid as catalyst (Scheme 6.3). The absence of aluminium chloride permits hydrolysis of the chloro substituent to take place. [Pg.281]

Quinizarin.—1 4-dihydroxyanthraquinone is of no use as a dye it has been found, as a general rule, that only those polyhydroxyquinones of the anthracene and naphthalene series (naphthazarin) which have their adjacent OH-groups in positions adjoining the carbonyl group are capable of forming colour lakes. [Pg.335]

The fact that dihydroxyanthraquinones can be directly oxidised to higher phenols with fuming sulphuric acid is of technical importance. Alizarin and quinizarin yield in this way the same 1 2 5 8-tetra-hydroxyanthraquinone (alizarin bordeaux), which can be further oxidised to the important compound anthracene blue (1 2 4 5 6 8-hexa-hydroxyanthraquinone). This dye is obtained technically from 1 5-or 1 8-dinitroanthraquinone by means of a very interesting reaction,... [Pg.335]

XII Quinizarin-2-car-boxylic acid — 1,A-Dihydroxyanthraquinone-2-carboxylic acid... [Pg.191]

Some other organic reagents have been also proposed for determination of Mg, e.g., Eriochrome Cyanine R [45], Alizarin S [46], o-cresolphthalein [47] and its derivatives [48], 1,2,7-trihydroxyanthraquinone [49], 1,8-dihydroxyanthraquinone (e = 1.2-10 at 510 nm) [50], and leuco-quinizarin [51]. Mg has been determined also with the use of emodin... [Pg.250]

Quinizarin-2-carboxylic acid (2-Carboxy-l,4-dihydroxyanthraquinone) Structure Ri = R4 = OH, R2 = COOH, R3 = H Isolation [110]... [Pg.664]

Liebermann discovered the reaction between nitrous acid and phenols and secondary amines named after him. He prepared amino-naphthols from nitro-naphthols, synthesised the dihydroxyanthraquinones anthrarufin and chrysazin, and studied the reduction of anthraquinone. Another dihydroxy-anthraquinone, quinizarin, was discovered by F. Grimm by heating hydro-quinone with phthalic anhydride. [Pg.790]

S Intermediates derived from anthraquinone. The principal primary intermediates are a- and jS- (1- and 2-) aminoanthraquinones and quinizarin-(1,4-dihydroxyanthraquinone), parent substances for more complex intermediates and dyes. a-Aminoanthraquinone is easily prepared by pressure amination of the a-sulphonic acid, itself obtained from a Hg-catalysed sulphonation from which ecological problems arise (section 2.7.7). jS-Aminoanthraquinone is made by amination of the 2-chloro compound (Figure 2.23). [Pg.86]


See other pages where 1.4- Dihydroxyanthraquinone quinizarin is mentioned: [Pg.85]    [Pg.245]    [Pg.96]    [Pg.287]    [Pg.121]    [Pg.85]    [Pg.245]    [Pg.96]    [Pg.287]    [Pg.121]    [Pg.283]    [Pg.184]    [Pg.184]    [Pg.516]    [Pg.191]    [Pg.44]    [Pg.1068]    [Pg.44]    [Pg.664]    [Pg.86]    [Pg.721]   
See also in sourсe #XX -- [ Pg.301 ]




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1.4- Dihydroxyanthraquinones

Dihydroxyanthraquinone

Quinizarin

Quinizarine

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