noun
definition
A red substance, 1,2-dihydroxyanthraquinone, extracted from madder root and used as a dye.
Examples of alizarin in a Sentence
Various sulphonic acids of anthraquinone are known, as well as oxy-derivatives, for the preparation and properties of which see Alizarin.
Perkin also had a large share in the introduction of artificial alizarin, the red dye of the madder root.
Numerous derivatives of alizarin are known.
Caustic soda is used in very large quantities in the manufacture of soap, paper, textile fabrics, alizarin and other colouring matters, and for many other purposes.
Alizarin was known to the ancients, and until 1868 was obtained entirely from madder root.
The first step in the synthetical production of alizarin was the discovery in 1868 of C. Graebe and C. Liebermann that on heating with zinc dust, alizarin was converted into anthracene.
The dibrominated product so obtained was then fused with caustic potash, the melt dissolved in water, and on the addition of hydrochloric acid to the solution, alizarin was precipitated.
The precipitated alizarin is then well washed and made into a paste with water, in which form it is put on to the market.
Lagodzinski (Berichte, 1895, 28, p. 1427) has synthesized alizarin by condensing hemipinic acid [(CH30)2C6H2(COOH)2] with benzene in the presence of aluminium chloride.
This compound is hydrolysed by hydriodic acid and alizarin is obtained.
Rubia tinctorum Madder The plant was formerly cultivated for its root which yields the dye alizarin.
The sky was painted upside down, painting the Raw Sienna at the base the introducing Alizarin Crimson then French ultramarine at the top.
Berzelius immediately appreciated the importance of this discovery, notwithstanding 1 The reader is specially referred to the articles Alizarin; Indigo; Purin and Terpenes for illustrations of the manner in which chemists have artificially prepared important animal and vegetable products.
In order to synthesize alizarin, they converted anthracene into anthraquinone and then brominated the quinone.
The sky was painted upside down, painting the Raw Sienna at the base the introducing Alizarin Crimson then French Ultramarine at the top.
This he did in 1869, thus securing for the Greenford Green works a monopoly of alizarin manufacture for several years.