4,5,5',7,7'-Pentabromo-2,2'-bi[1H-indole]-3,3'-diol bis(sulfuric acid sodium) salt

Preparation

(a) in the presence of ?Pyridine , with Chlorosulfonic acid treatment C.I. 73070 leuco: (b) in the Pyridine with metal (such as copper, iron, zinc, etc) and Sulfur trioxide source (such as Sulfur trioxide, Chlorosulfonic acid or Methyl chlorosulfonate, etc.) processing C.I. 73070. The above two kinds of situation after alkaline, filter out insolubles, remove Pyridine and salting out.

Properties and Applications

blue. Water-soluble blue. Dyes may contain soluble vat dyes C.I.73076,C.I.?Vat Blue 48 leuco.

Standard	Ironing Fastness	Chlorine bleach	Light Fastness	Mercerized	Oxygen bleach	Soaping
						Fading	Stain
AATCC	3	2-3	3-4	4	3