the preparation methods and C.I. Sulphur Blue 13 (C.I. 53450) similar, but the reaction should be Copper sulfate monohydrate existence. Will 4-(4-(Phenylamino)phenylimino)cyclohexa-2,5-dienone in Copper sulfate monohydrate Sodium polysulfide solution presence and in return, in 115 ℃ heating 50 hours, then 70 ℃ blowing air, make its precipitation.
