Direct Orange 33

Preparation

4-(4-Aminophenyl)benzenamine double nitriding, respectively with 2-Hydroxybenzoic acid and?3-(3-Methyl-5-oxo-4-,5-dihydropyrazol-1-yl)naphthalene-1,5-disulfonic acid?coupling, 3,3′-Dimethylbenzidine diazo, respectively with the 2,4-Diamino-5-methylbenzenesulfonic acid and 4-Methylsalicylic acid?coupling.

Properties and Applications

yellow orange. Soluble in water for golden brown, soluble in ethanol. The strong sulfuric acid for product red to brown, diluted blue for Tracy.?dye solution was added concentrated hydrochloric light olive brown yellow, with precipitation; adding concentrated sodium hydroxide solution was orange-brown.