Title: Brazilin
CAS Registry Number: 474-07-7
CAS Name: (6aS-cis)-7,11b-Dihydrobenz[b]indeno[1,2-d]pyran-3,6a,9,10(6H)-tetrol
Additional Names: brasilin; C.I. Natural Red 24; C.I. 75280
Molecular Formula: C16H14O5
Molecular Weight: 286.28
Percent Composition: C 67.13%, H 4.93%, O 27.94%
Literature References: (May crystallize as the mono- or hemihydrate). From Caesalpinia echinata Lam. (Brazil-wood), or C. sappan L. (sappan-wood), Leguminosae. Isoln and structure: Perkin et al., J. Chem. Soc. 1928, 1504; Pfeiffer et al., Ber. 63, 1301 (1930). Synthesis of (±)-form: Dann, Hofmann, Ann. 667, 116 (1963); Kirkiacharian, Billet, Bull. Soc. Chim. Fr. 1972, 3292. Synthesis, resolution: Morsingh, Robinson, Tetrahedron 26, 281 (1970). Stereochemistry: Craig et al., J. Org. Chem. 30, 1573 (1965); Colour Index vol. 4 (3rd ed., 1971) p 4628. Review: Robinson, Bull. Soc. Chim. Fr. 1958, 125-134.
Properties: Amber-yellow crystals; turn orange in air and light. Dec above 130°. Sol in water, freely in alcohol, ether, also in alkali hydroxide solns with carmine-red color. Protect from air and light.
Use: Chiefly as a dye. Has also been recommended as indicator in acid-base titrations; acids = yellow, alkalies = carmine-red.
Brefeldin A Brequinar Bretylium Tosylate Brevetoxins Brilliant Blue FCF

CAS number 474-07-7 N
PubChem 73384
ChemSpider 66104 YesY
Jmol-3D images Image 1
Image 2
Molecular formula C16H14O5
Molar mass 286.28 g mol−1
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Brazilin is a red pigment obtained from the wood of the brazilwood family (Caesalpinia sp), and is also known as Natural Red 24. Brazilin has been used since at least the Middle Ages to dye fabric, and has been used to make paints and inks as well. The specific color produced by the pigment depends on its manner of preparation: in an acidic solution brazilin will appear yellow, but in an alkaline preparation it will appear red. Brazilin is closely related to the blue-black dye hematoxylin, having one less hydroxyl group. Brazilein is the name for the oxidized pigment.[1]