128-94-9Relevant articles and documents
An improved practical synthesis of leuco-1,4,5,8-tetrahydroxyanthraquinone
Chang,Cheng
, p. 1893 - 1900 (1995)
Leuco-1,4,5,8-tetrahydroxyanthraquinone was prepared from chrysazin by nitration and reduction with iron powder, followed by treatment with sodium hydrosulfite in alkaline solution. This method is suitable for scaling, and is significant and improved over literature methods.
Process for the manufacture of aminohydroxyanthraquinones
-
, (2008/06/13)
The invention relates to a process for the manufacture of an aminohydroxyanthraquinone of the formula STR1 wherein both of X are hydrogen or one X is --NH2 and the other is --OH and Z is hydrogen, C1 -C4 alkyl or carboxyl, with the proviso that, if Z is C1 -C4 alkyl or carboxyl, both of X must be hydrogen, which process comprises reacting a nitroanthraquinone of the formula STR2 wherein both of Y are hydrogen or one Y is --NO2 and the other is hydrogen and Z is as defined for formula (1), with the proviso that, if Z is C1 -C4 alkyl or carboxyl, both of Y must be hydrogen, in an aprotic dipolar solvent, with an alkali metal azide or alkaline earth metal azide, in the temperature range between 0° and 30° C. The reaction products are disperse dyes or intermediates for obtaining vat dyes and disperse dyes.
