Use
naphthols: Two phenols derivedfrom naphthalene with the formulaC10H7OH, differing in the position ofthe –OH group. The most importantis naphthalen-2-ol (β-naphthol),with the –OH in the 2-position. Itis a white solid (r.d. 1.28; m.p.123–124°C; b.p. 295°C) used in rubberas an antioxidant. Naphthalen-2-ol will couple with diazonium salts atthe 1-position to form red azo compounds,a reaction used in testing forthe presence of primary amines (bymaking the diazonium salt andadding naphthalen-2-ol).