Naphthol

Naphthols are chemical substances, which are also referred to as hydroxynaphthalenes, as they are derivatives of naphthalene, in which one or more hydrogen atoms are replaced by hydroxyl groups. The simplest naphthols are 1-naphthol ( α -naphthol, 1- hydroxynaphthalene ), and 2-naphthol ( β - naphtol, 2- hydroxynaphthalene ).

Properties

Naphthols react chemically similar to phenols, but are usually more responsive. Naphthols are difficult in cold water, more soluble in hot water. Since naphthols such as the phenols are weak acids, they are more soluble in water than in dilute sodium hydroxide solution. Organic solvents such as ethanol, ether and benzene, naphthols dissolve well.

Use

The naphthols are often for the synthesis of azo dyes, tanning agents, dyeing and printing auxiliaries, used preservative for glue, wood and leather. Thus, for example, 2- naphthol is coupled with 4 -nitroaniline to Para Red: