1,2,4-Trichloro-7-amino-3H-isophenoxazin-3-one?and sodium polysulphide?aqueous solution in the presence of glycerol heating, in 75 ~ 98 ℃ reflux 7 hours, add SODIUM chloride cure completely, then heating, in 103 ~ 104 ℃ reflux 24 hours. This is by thiazine Chloranil and 6 – amino – 3 – methyl – thiophenol zinc salt in Etanol solution to return next condensation and have to (BIOS 1155, 31). In the same way,1,2,4 – trichloro -7- iso-ethoxy-3H-phenothiazine-3-one system color slant blue dye (FIAT 1313,3,243).