Some of the phenols discussed below are:

1. Cresols,
2. Resorcinol, and
3. Naphthols.

Cresols

Cresols (or hydroxytoluene) belonging to the family of methyl phenols have the molecular formula C₇H₈O. They are aromatic organic compounds which either occur naturally or are manufactured.

Cresols are obtained as a mixture of three stereoisomers (molecules having same number and type of atoms but different atomic arrangements) from coal tar or petroleum. This mixture is referred to as tricresol or cresylic acid. The odour of cresols is characteristic to that of other simple phenols, indicative of the smell of coal tar.

Structure

A cresol molecule has a methyl group substituted on phenol ring. It may exist in any of its three forms (isomers), ortho-cresol (o-cresol), meta-cresol (m-cresol), and para cresol (p-cresol).

Uses

Cresols have the following uses:

1. They are used as germicides.
2. They are used as disinfectants and antiseptics even in low concentrations.
3. They are also used in sheep-dips (disinfectants containing insecticides and pesticides) in low concentrations.
4. They are important components of creosote (a wood preservative produced as a byproduct of coal tar distillation).
5. They provide antibacterial and insecticidal properties to creosote.
6. Being phenol derivatives, they can be used in phenol-formaldehyde resins.
7. The m-cresol form is used in making photographic developers and explosives.
8. The p-cresol form is converted into Butylated Hydroxytoluene (BHT, an antioxidant in foods).

Resorcinol

Resorcinol is a 1,3-isomer (or meta-isomer) of benzenediol, having the molecular formula C₆H₆O₂. It is a white crystalline solid; however if not completely pure it turns pink when exposed to light.

Large quantities of resorcinol are produced by sulphonation of benzene with fuming sulphuric acid, and fusing the so obtained benzene disulphonic acid with caustic soda.

Structure

Uses

Resorcinol has the following uses:

1. It is used for manufacturing resins, plastics, dyes, medicines, and other organic chemical compounds.
2. Pharmaceutically it is used as an antiseptic and disinfectant in topical products used to treat skin disorders and infections (e.g., acne, seborrheic dermatitis, eczema, psoriasis, corns, calluses, and warts).
3. It possesses a keratolytic activity.
4. It works by removing hard, scaly, or roughened skin.

Naphthols

Naphthols, either 1-naphthol ( α-naphthol) or 2-naphthol ( β-naphthol), are naphthalene derivatives, having the molecular formula C₁₀H₈O. They are crystalline organic compounds belonging to the family of phenols.

1-Naphthol is obtained by heating 1-naphthalene sulphonic acid with caustic alkali or by heating 1-naphthylamine with water under pressure. 2-Naphthol (most important chemical intermediate based on naphthalene) is obtained by the fusion of 2-naphthalene sulphonic acid with caustic soda.

Structure

Naphthol has a hydroxyl group bonded to a naphthalene ring. It may exist as one of its two isomers, either 1-naphthol or 2-naphthol.

Uses

Naphthols have the following uses:

1. They are used for manufacturing dyes and dye intermediates.
2. They are also used in other areas of chemical industries.
3. 1-Naphthol is used for making several dyes, and it is converted into large amounts of compounds incorporated into other dyes.
4. 2-Naphthol is converted into various dyes, dye intermediates, tanning agents, antioxidants, and antiseptics.