CAS Registry Number: 81-77-6
CAS Name: 6,15-Dihydro-5,9,14,18-anthrazinetetrone
Additional Names: N,N¢-dihydro-1,2,1¢,2¢-anthraquinonazine
Molecular Formula: C28H14N2O4
Molecular Weight: 442.42
Percent Composition: C 76.01%, H 3.19%, N 6.33%, O 14.47%
Literature References: Vat dye discovered by René Bohn (1901). Prepn: Fierz-David, Blangey, Grundlegende Operationen der Farbenchemie (Vienna, 5th ed., 1943) pp 304-305; Thielert, Bauman, US 2693469 (1954 to Bayer); Sutter, Fioroni, US 2831860 (l958 to Ciba); Kastner, US 3138612 (1964 to Allied Chem.). Structure: Weinstein, Merrit, J. Am. Chem. Soc. 81, 3759 (1959).
Properties: Blue powder, dec 470-500°. uv max on cellophane film: 278 nm. Practically insol in organic solvents. Sol in concd H2SO4, in dil alkali solns. Indanthrene Blue R, the usual commercial grade, is extremely stable to light and heat, but sensitive to chlorine. A purer grade, which is not as sensitive to chlorine, is sold as Indanthrene Brilliant Blue FF.
Absorption maximum: uv max on cellophane film: 278 nm
Use: Mainly to dye cotton.