naphthol

C₁₀H₇OH. Two isomeric phenols, obtained by substituting –OH for one hydrogen atom of naphthalene. Both are present in coal tar, and are starting materials for dyes.

Naphthol, or hydroxynaphthalene or naphthalenol, is either of two colorless crystalline solids with the formula C10H7OH. They are positional isomers differing by the location of the hydroxyl group on naphthalene. Naphthol is the naphthalene homologue of phenol, with the hydroxyl group being more reactive than in the phenols. For example, β-naphthol reacts to form BINOL.