(a) 3H-indol-3-one,2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro- in chlorosulfonic acid bromide, (b) Indigo under pressure to use too much bromide bromide (With or without an inert solvent may be), its product bromide (mainly seven bromide Indigo) using bisulphite processing, remove unstable (mainly “type” bromide) bromide (GP 236902).
Properties and Applications
blue. Insoluble in Etanol. In concentrated sulfuric acid for blue, dilution after blue precipitation; In the basic insurance powder solution for yellow; In the acidic insurance powder solution for pale yellow. Dye aqueous solution with sodium hydroxide don’t change color.
