6-[1-(hydroxyamino)ethylidene]-4-methylcyclohexa-2,4-dien-1-one

2,5-二甲基苯并恶唑

4-(2-hydroxy-5-methyl-phenylazo)-benzenesulfonic acid , sodium-salt

对甲酚

2-硝基-4-甲苯酚