Document Type and Number:
Japanese Patent JPS5075218
Kind Code:
A
Abstract:
Alpha-dihydroxyanthraquinones used as intermediates in the synthesis of many dyestuffs, such as the Alizarin Saphirols (e.g. Color Constitution No. 63000, 63005, 63010, 63011, 63315 and 63610) can be replaced on an equimolar basis by alpha-di(lower alkoxy)anthraquinones. The alpha-di(lower alkoxy) anthraquinones can be converted in a single step, by treatment with oleum, to the corresponding alpha-dihydroxyanthraquinone-beta-disulfonic acids in almost quantitative yield. The corresponding diamine is obtained by dinitrating followed by reduction of the nitro groups. The known intermediate, leuco 1,4,5,8-tetrahydroxyanthraquinone (see C.I. No. 62500) can be obtained either by reduction of the diamine or by reduction of the dinitro compound. In one embodiment, the alpha-di(lower alkoxy)anthraquinone is obtained from dinitroanthraquinone by treatment thereof with methanol and KOH.
Application Number:
JP12651374A
Publication Date:
June 20, 1975
Filing Date:
November 01, 1974
Export Citation:
International Classes:
C09B1/12; C07C46/00; C07C46/10; C07C50/34; C07C205/47; (IPC1-7): C07C39/12; C07C49/75; C07C143/36; C09B1/12