Direct Brown 185

Preparation

2-Amino-5-(4-aminophenyl)benzenesulfonic acid double nitriding, Followed by coupling with ?2-Hydroxybenzoic acid?and Resorcinol coupling.

Properties and Applications

red light brown. Soluble in water for yellow orange, slightly soluble in alcohol. The strong sulfuric acid to red light purple, diluted for brown. The dye solution to join strong hydrochloric acid for orange brown, have precipitation; With strong sodium hydroxide solution for red orange brown.