C.I.73801;Anthrasol Blue AGG;Indigosol Blue AGG;Solubilised Vat Blue 8;Sandozol Printing Blue 2G;C.I.Solubilised Vat Blue 8;C.I.Solubilised Vat Blue 8:C.I.738001;disodium 5-chloro-2-[4-chloro-1-(sulphonatooxy)-2-naphthyl]-7-methoxy-4-methyl-1H-indol-3-yl sulphate;disodium,[4-chloro-2-(5-chloro-7-methoxy-4-methyl-3-sulfonatooxy-1H-indol-2-yl)naphthalen-1-yl] sulfate;5-Chloro-2-[4-chloro-1-(sodiosulfooxy)-2-naphthalenyl]-7-methoxy-4-methyl-1H-indol-3-ol (sulfuric acid sodium) salt
(a) in the presence of Pyridine , with Chlorosulfonic acid treatment C.I. Vat Blue 8 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. Vat Blue 8. The above two kinds of situation after alkaline, filter out insolubles, remove Pyridine and salting out.
