Alizarin cyanine R

Alizarin cyanine R
Names
	IUPAC name 1,2,4,5,7,8-Hexahydroxyanthraquinone
	Other names Alizarine Cyclamine R; 1,2,4,5,7,8-Hexahydroxy-9,10-anthracenedione;
Identifiers
CAS Number	6373-25-7;
3D model (JSmol)	Interactive image;
ChemSpider	11516790;
PubChem CID	22643669;
UNII	S3OT592S9T;
CompTox Dashboard (EPA)	20213150;
	InChI InChI=1S/C14H8O8/c15-3-1-5(17)11(19)9-7(3)13(21)8-4(16)2-6(18)12(20)10(8)14(9)22/h1-2,15-20H Key: NEVTZWLESVDYDA-UHFFFAOYSA-N;
	SMILES C1=C(C2=C(C(=C1O)O)C(=O)C3=C(C2=O)C(=CC(=C3O)O)O)O;
Properties
Chemical formula	C14H8O8
Molar mass	304.022 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Alizarin cyanine R is an anthraquinone dye and belongs to the mordant dyes^[1]

History

Alizarin cyanine R was discovered by R. E. Schmidt in 1891.^[1]

Representation

Alizarin cyanine R can be obtained by oxidation of alizarin Bordeaux with manganese dioxide, analogous to the oxidation of alizarin to purpurin.^[2]

Another route involves Chinalizarin (C.I. 58500), which is treated with manganese dioxide in sulfuric acid, followed by oxidation of the resulting quinone and subsequent reduction (chemistry) with sulfurous acid.^[1]

A further possibility is the oxidation of anthrapurpurin (C.I. 58255) with Oleum.^[1]

Use

This dye yields a violet aluminum lacquer and a blue chrome lacquer.^[2]

Differentiation from C.I. Mordant Blue 32

The Colour Index lists C.I. Mordant Blue 32 under the constitution number C.I. 58605^[1] and describes it as 1,2,4,5,6,8-hexahydroxy-9,10-anthraquinone, which was discovered by R. Bohn in 1891.

	C.I. Mordant Blue 32
Name	1,2,4,5,6,8-Hexahydroxy-9,10-anthracenedione
Structural formula
CAS number	61169-36-6
PubChem	80762
ChemSpider	72916
Wikidata	Q27104411
Sum formula	C₁₄H₈O₈
Molar mass	304.022 g·mol⁻¹

SciFinder lists C.I. Mordant Blue 32 under the CAS number 6373-24-6, in which five hydroxy groups are located at the 1, 2, 4, 5, and 8 positions of the anthraquinone, while the sixth hydroxy group is variably assigned to either the 6 or 7 position.

According to the Colour Index, the respective technical products contain the alternate isomer as an impurity.^[1]

References

^ ^a ^b ^c ^d ^e ^f Society of dyers & colourists, ed. (1971), "CL Solvent Red 26 (Red)", Colour Index, vol. 4 (3 ed.), Bradford & London: Lund Humphries, ISBN 0901956066, retrieved 2025-12-17{{citation}}: CS1 maint: work parameter with ISBN (link)
^ ^a ^b "Coloriasto: The Chemistry of Dyestuff. Dyestuffs. XXIII. Oxyketone Dyestuffs". Coloriasto. 2016-12-27. Retrieved 2025-12-29.

[ColourIndex-1] ^ ^a ^b ^c ^d ^e ^f Society of dyers & colourists, ed. (1971), "CL Solvent Red 26 (Red)", Colour Index, vol. 4 (3 ed.), Bradford & London: Lund Humphries, ISBN 0901956066, retrieved 2025-12-17{{citation}}: CS1 maint: work parameter with ISBN (link)

[Colori-2] "Coloriasto: The Chemistry of Dyestuff. Dyestuffs. XXIII. Oxyketone Dyestuffs". Coloriasto. 2016-12-27. Retrieved 2025-12-29.

[1]

[2]