Lithol Rubine BK

Lithol Rubine BK

IUPAC name Calcium (4Z)-4-[(4-methyl-2-sulfonatophenyl)hydrazono]-3-oxo-2-naphthalenecarboxylate
Other names Pigment Rubine, Carmine 6B, Brilliant Carmine 6B, Permanent Rubin L6B, Litholrubine, Latolrubine, C.I. Pigment Red 57, C.I. Pigment Red 57:1, D&C Red No. 7, or C.I. 15850:1; E180
Identifiers
CAS number	5281-04-9^Y
PubChem	9571018
ChemSpider	17215383^Y
UNII	ECW0LZ41X8^Y
Jmol-3D images	Image 1
SMILES [Ca+2].[O-]S(=O)(=O)c3cc(C)ccc3/N=N/c1c2ccccc2cc(C([O-])=O)c1O
InChI InChI=1S/C18H14N2O6S.Ca/c1-10-6-7-14(15(8-10)27(24,25)26)19-20-16-12-5-3-2-4-11(12)9-13(17(16)21)18(22)23;/h2-9,21H,1H3,(H,22,23)(H,24,25,26);/q;+2/p-2/b20-19+;^Y Key: PZTQVMXMKVTIRC-RZLHGTIFSA-L^Y InChI=1/C18H14N2O6S.Ca/c1-10-6-7-14(15(8-10)27(24,25)26)19-20-16-12-5-3-2-4-11(12)9-13(17(16)21)18(22)23;/h2-9,21H,1H3,(H,22,23)(H,24,25,26);/q;+2/p-2/b20-19+; Key: PZTQVMXMKVTIRC-LGRYAOMWBK
Properties
Molecular formula	C₁₈H₁₂CaN₂O₆S
Molar mass	424.44 g/mol
Appearance	Red powder
Solubility in water	slightly soluble in hot water, insoluble in cold water and ethanol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Lithol Rubine BK is a reddish synthetic azo dye. It has the appearance of a red powder. It is slightly soluble in hot water, insoluble in cold water, and insoluble in ethanol. When dissolved in dimethylformamide, its absorption maximum lies at about 442 nm. It usually comes as a calcium salt.

It is used to dye plastics, paints, printing inks, and for textile printing. It is normally used as a standard magenta in the three and four color printing processes.

When used as a food dye, it has E number E180. It is used to color cheese rind as well as a component in some lip balms. It is banned in some countries.

Lithol Rubine BK

References