C.I. Direct Orange 71

Preparation

in reflux conditions, sodium hydroxide solution in (E)-2-(2-sulfo-4-nitrostyryl)-5-nitrobenzenesulfonic acid with 4-Aminobenzoic acid diazo with aniline?coupled with product heating, then use glucose and sodium hydroxide treatment.

Properties and Applications

red light orange. Soluble in water for palm light orange, soluble in ethanol for light golden brown. In the strong sulfuric acid as dark blue, diluted for brown. The dye solution to join strong hydrochloric acid have dark brown precipitation, add thick sodium hydroxide solution have brown light orange precipitation. Used for cellulose fiber dyeing, 90 ℃ maximum when affinity, Exhaust dyeing.