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. |