From Wikipedia, the free encyclopedia
  (Redirected from Quinizarin)
Jump to navigation Jump to search
Skeletal formula
Ball-and-stick model
IUPAC name
Other names
Quinizarin; Solvent Orange 86
3D model (JSmol)
ECHA InfoCard 100.001.245
Molar mass 240.21 g/mol
Appearance Orange or red-brown crystalline powder
Melting point 198 to 199 °C (388 to 390 °F; 471 to 472 K)
Boiling point 450 °C (842 °F; 723 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☑Y verify (what is ☑Y☒N ?)
Infobox references

1,4-Dihydroxyanthraquinone, also called quinizarin or Solvent Orange 86, is an organic compound derived from anthroquinone. Quinizarin is an orange or red-brown crystalline powder. It is formally derived from anthraquinone by replacement of two hydrogen atoms by hydroxyl (OH) groups. It is one of ten dihydroxyanthraquinone isomers and occurs in small amounts (as a glycoside) in the root of the madder plant, Rubia tinctorum.[1]


Quinizarin is produced by the reaction of phthalic anhydride and 4-chlorophenol followed by hydrolysis of the chloride:[2]

C6H4(CO)2O + ClC6H4OH → C6H4(CO)2C6H2(OH)Cl + H2O
C6H4(CO)2C6H2(OH)Cl + H2O → C6H4(CO)2C6H2(OH)2 + HCl

It can also be prepared less efficiently from phthalic anhydride and hydroquinone.


Quinizarin is an inexpensive dye that is used to colour gasoline and some heating oils. It is used as an intermediate for the synthesis of indanthrene- and alizarin-derived dyes. The OH groups can be replaced by chloride. Chlorination and bromination afford other dyes. Amination (replacement of one OH by ArNH) with aniline derivatives followed by sulfonation affords other dyes such as Acid Violet 43. It is also used to form lake pigments with calcium, barium, and lead.[2]

Quinizarin sample (Historic Dye Collection of TU Dresden).

See also[edit]


  1. ^ Derksen, G. C. H.; Niederländer, H. A. G.; van Beek, T. A. (2002). "Analysis of Anthraquinones in Rubia tinctorum L. by Liquid Chromatography Coupled with Diode-Array UV and Mass Spectrometric Detection". Journal of Chromatography A. 978 (1–2): 119–127. doi:10.1016/S0021-9673(02)01412-7.
  2. ^ a b Bien, H.-S.; Stawitz, J.; Wunderlich, K., "Anthraquinone Dyes and Intermediates", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a02_355