Alizarin

CA Index Name 9,10-Anthracenedione, 1,2-dihydroxy-Other Names Alizarin B Anthraquinone, 1,2-dihy-droxy- 1,2-Anthiaquinonediol l,2-Dihydroxy-9,10-an-thracenedione l,2-Dihydioxy-9,10-anthraquinone 1,2-Dihydroxyanthiaquinone 1,2-Dihydroxy anthrachinone Acid Metachrome Red B Acid Mordant Red B Alizarin Alizarin Red Alizarina Alizarine Alizarine 3B Alizarine B Alizarine Indicator Alizarine L Paste Alizarine Lake Red 2P Alizarine Lake Red 3P Alizarine Lake Red IPX Alizarine NAC Alizarine Paste 20 percent Bluish Alizarine Red Alizarine Red B Alizarine Red B2 Ah-zarine Red IP Alizarine Red IPP Alizarine Red L C Ext. Red 62 C.I. 58000 C.I. Mordant Red 11 Certiqual Alizarine C.I. Pigment Red 83 D And C Orange Number 15 Deep Crimson Madder 10821 Eljon Madder Mitsui Alizarine B Mordant Red 11 NSC 7212 Sanyo Carmine L2B Turkey Red 

Synthesis Synthetic methods Staining Applications Bacteria human adipose-derived stem cells multipotent adult progenitor cells parasite lips skin hairs keratin fibers  

Biological Applications Detecting microorganisms treating dermatological conditions  

Industrial Applications Solar cells plasma dis-play panel antireflective coatings chemical mechanical polishing optical recording materials inks paints adhesives thermoplastics detergents textiles wood  

Safety/Toxicity Acute oral toxicity carcinogenicity clastogenicity environmental toxicity estro-genicity genotoxicity hypersensitivity mu-tagenicity photoinduced toxicity  

A mixture of 2 g. of potassium chlorate, 30 g. of commercial sodium hydroxide, 10 g. of finely powdered sodium /3-anthraquinone-sulphonate ( silver salt ), and 40 c.c. of water is heated for twenty hours at 170° (oil bath) in an autoclave or in an iron tube with screwed-on cap. The cooled melt is repeatedly extracted with hot water and the extracts, after being combined and filtered, are acidified while hot with excess of hydrochloric acid, which precipitates the alizarin. When the mixture has cooled the precipitate is collected at the pump, washed successively with dilute hydrochloric acid and water, and dried. 

For purification the crude product is boiled with glacial acetic acid (preferably in the extraction apparatus shown in Fig. 27). Fine red needles melting point 289°. Sublimation in a vacuum from a sausage flask is also to be recommended the sausage should be fixed low down and the bulb completely immersed in a nitrate bath (equal parts of potassium and sodium nitrates). Much poorer yields of alizarin are obtained by using an open round-bottomed flask at 189°-190°. 

Alizarin or l 2-dihydroxyanthraquinone is one of the most important dyes. Like indigo, the dye occurs in the plant (the madder root) as the glucoside of the leuco-compound. The cultivation of the madder plant, which, chiefly in southern France, extended over large areas, was brought to an end by the synthesis of the dye from the anthracene of coal-tar (Graebe and Liebennann, 1869). By distillation with zinc dust according to the method of Baeyer, these two chemists had previously obtained anthracene from alizarin. 

Anthracene can be oxidised directly to its wi so-quinone, anthra-quinone, by means of chromic acid. For almost all its reactions the middle ring of anthracene provides the point of attack. 

Experiment.—Dissolve 1 g. of purest anthracene in just sufficient good glacial acetic acid at the boiling point without further heating add 3 c.c. of concentrated sulphuric acid and, drop by drop, 4 g. of sodium dichromate dissolved in a quite small amount of water. (Neglect any turbidity or precipitate which appears after the addition of the sulphuric acid.) A very vigorous reaction occurs and the chromic acid is used up almost immediately after all the dichromate has been added boil for five minutes longer. Dilute the solution. The anthraquinone separates in a flocculent condition. After 

Upon heating anthraquinone with fuming sulphuric acid at 160° for about 1 hour, the main product Is anthraquinone-p-sulphonic acid, which is isolated as the sparingly soluble sodium salt. The latter when heated imder pressure with sodium hydroxide solution and an oxidising agent (sodium or potassium chlorate) yields first the corresponding hydroxy compound further hydroxy-lation occurs in the a-position through oxidation by the chlorate and 1 2-di-hydroxyanthraquinone (alizarin) is formed. 

Sodium anthraquinone- -sulphonate ( silver salt ). Place 60 g. of fuming sulphuric acid (40-50 per cent. SOj) in a 250 or 500 ml. round-bottomed flask and add 50 g. of dry, finely-powdered anthraquinone (Section IV, 145). Fit an air condenser to the flask and heat the mixture slowly in an oil bath, with occasional shaking, so that at the end of 1 hour the temperature has reached 160°. Allow to cool and pour the warm mixture carefully into a 2 htre beaker containing 500 g. of crushed ice. Boil for about 15 minutes and filter off the unchanged anthraquinone at the pump. Neutrahse the hot filtrate with sodium hydroxide and allow to cool, when the greater part of the sodium anthraquinone- -sulphonate separates as silvery glistening plates ( silver salt ). Filter these with suction and dry upon filter paper or upon a porous plate. A second crop of crystals may be isolated by concentration of the fitrate to half the original volume. The yield is 40-45 g. 

Alizarin. Dissolve successively in 75 ml. of water 6 g. of potassium chlorate, 20 g. of sodium anthraquinone-p-sulphonate and 75 g. of sodium hydroxide. Transfer the mixture to a 500 ml. autoclave (compare S ion VI,4) and heat for 20 hours at 170°. After cooUng, scrape out 

Indigo carmine commonly consists of indigotindisulphonic acid or its sodium salt, which is sold as a moist paste or in blue balls or lozenges with reddish reflection. Indigotinmonosulphonic acid (iindigo purple) is little used. Pure indigo carmine is completely soluble in water, from which it is reprecipitated by addition of sodium chloride. Commercial carmines of low quality leave a more or less abundant greenish residue insoluble in water. 

Acidity.—i gram of the carmine is dissolved in ioo c.c. of water and then treated with 32 grams of pure sodium chloride, shaken and filtered, the precipitate being washed with salt water. The acidity is determined in the liquid by titrating with decinormal KOH in presence of phenolphtha-lein, the result being calculated as sulphuric acid. 

Artificial Organic Dyes.—Indigo carmine may be adulterated with artificial organic dyes, especially aniline blue. If silk is dyed with an acidified solution of the carmine and then washed and boiled with water, the fibre will become colourless if the carmine is pure, but remains blue if aniline blue is present. 

Also by oxidising the carmine solution with permanganate for the determination of the mdigotin, many artificial organic dyes may be detected thus, pure indigo carmine solution remains yellow, whereas it may be bluish, violet, grey or reddish in presence of artificial organic dyes. 

Natural alizarin of madder is now scarcely ever used, commercial alizarin being obtained artificially. It forms either a wet, ochre-yellow paste, usually containing about 20% of solid matter (sometimes as much as 40 or 60%) or dry powder or lumps 

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Anlhraquinone-2-su phonic acid. The sodium salt, commonly called silver salt , is used for the preparation of alizarin and 2-aminoanthraquinone and to prepare Fieser s solution. Aminoanthraquinone derivatives are the basis of many dyestuffs. 

Addition of ammonium hydroxide to an aluminium salt in solution in presence of alizarin, gives a pink precipitate. 

The way a synthesis is planned has changed substantially over time. Until the beginning of the 20th century many noteworthy syntheses had been developed, c.g., of alizarin (C. Gracbc, C, Licbermann, 1869) and indigo (A, Bacycr, 1878). 

Anthraquinone is of great technical importance, as many of its derivatives form valuable dyes notable among these are the hydroxy-derivatives (alizarin, etc.)y the amino-derivatives (indanthrene, etc.) and the sulphonic acids. 

Benzoquinone, p-toluquinone, 1 2-naphthoquinone,, naphthoquinone, anthraquinone,, io-phenanthraquinone, alizarin. 

Anthraquinone and alizarin are unaffected by sulphurous acid. Phenanthraquinone is reduced in warm ethanolic solution by SO2 water to hydrophenanthraquinone, m.p. 147°. 1,2-Naphthoquinone gives the corresponding hydronaphthoquinone, m.p. 60°. Toluquinone gives toluhydroquinone, m.p. 124 . 

Alizarin dissolves in aqueous NaOH solution giving a purple solu tion. Calcium hydroxide will precipitate a blue sdt from this solution. Anthraquinone is unaffected by NaOH solution. 

Plane one drop of the solution upon zireonium-alizarin-S test paper. A yellow eolour on the red paper indicates the presenee of fluoride. 

Quinones that are based on the anthracene ring system are called anthraqumones Alizarin is one example of an anthraqumone dye... 

Qumones are colored p benzoqumone for example is yellow Many occur natu rally and have been used as dyes Alizarin is a red pigment extracted from the roots of the madder plant Its preparation from anthracene a coal tar derivative m 1868 was a significant step m the development of the synthetic dyestuff industry... 

Alizarin, dihydroxyanthraquinone (indicator) dissolve 0.1 g in 100 mL alcohol pH range yellow 5.5-6.8 red. 

Indicator solutions a number of indicator solutions are listed in this section under the names of the indicators e.g., alizarin, aurin, azolitmin, et al., which follow alphabetically. See also various index entries. 

Rosolic acid, aurin, corallin, corallinphthalein, 4,4 -dihydroxy-fuchsone, 4,4 -dihydroxy-3-methyl-fuchsone (indicator) dissolve 0.5 g in 50 mL alcohol and dilute with water to 100 mL. Salicyl yellow (indicator) see alizarin yellow GG. 

Structure of (a) alizarin garnet R, and (b) its metal-ligand complex with AP+. 

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