(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).
