1,2,4-Trichloro-7-amino-3H-isophenoxazin-3-one and Sodium polysulfide ethanol solution heating, and in 80 ~ 81 ℃ under reflux 24 hours, in steamed out after ethanol, add salt precipitation, and washing brine precipitation. This oxazine is by 2,3,5,6-Tetrachlorocyclohexa-2,5 -diene-1,4-dione and 2-Amino-5-nitrophenol?condensation, then in 30 ~ 40 ℃ with Sodium hydroxide powder and insurance and reduction.
