4-aminoazobenzene-3,4'-disulfonic acid
4-aminoazobenzene-3,4'-disulfonic acid
A member of the class of azobenzenes that is azobenzene in which one of the phenyl groups is substituted at the <em>para</em> position by a sulfo group, while the other is substituted at a <em>meta</em> position by a sulfo group and at the <em>para</em> position by an amino group. The disodium salt is the biological stain 'fast yellow'.