disodium 7,17-dichloro-10,20-dihydrodiindeno[2,1-b:2',1'-m]triphenodioxazinedisulphonate

9H-fluoren-2-amine and 2,3,5,6-Tetrachlorocyclohexa-2,5 -diene-1,4-dione condensation, in boiling adjacent two chlorobenzene (or nitrobenzene) with 4-Methylbenzene-1-sulfonyl chloride cyclization, again with hair smoke sulfuric acid were two, and finally into two sodium salt.

bright purple. Soluble in water for purple.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	2-3	4	6	1-2		2-3