2-Methylnaphthalene

2-Methylnaphthalene

2-Methylnaphthalene is a polycyclic aromatic hydrocarbon (PAH) compound with the chemical formula C11H10. It is a colorless liquid that is insoluble in water but soluble in organic solvents. 2-Methylnaphthalene is commonly used as a starting material in the synthesis of various chemicals and is also found in coal tar and crude oil.

Properties and Structure

2-Methylnaphthalene consists of a naphthalene ring with a methyl group attached to one of the carbon atoms. It has a molecular weight of 142.20 g/mol and a melting point of -29 °C. The compound has a boiling point of 242 °C and a density of 1.01 g/cm³.

The structure of 2-Methylnaphthalene is planar, with the methyl group extending out of the plane of the naphthalene ring. This structure gives the compound its unique physical and chemical properties.

Synthesis

2-Methylnaphthalene can be synthesized through various methods. One common method involves the alkylation of naphthalene with methyl chloride in the presence of a strong base, such as sodium hydroxide. This reaction results in the substitution of a hydrogen atom on the naphthalene ring with a methyl group.

Another method of synthesis involves the selective methylation of naphthalene using a catalyst, such as aluminum chloride. This method allows for the controlled addition of a methyl group to the desired position on the naphthalene ring.

Uses

2-Methylnaphthalene has several industrial applications. It is commonly used as a solvent in the production of dyes, resins, and rubber. The compound is also used as a starting material in the synthesis of pharmaceuticals, agrochemicals, and fragrances.

In addition to its industrial uses, 2-Methylnaphthalene is also used in research laboratories as a reference standard for analytical techniques, such as gas chromatography. Its unique chemical properties make it a valuable tool for identifying and quantifying other compounds.

Safety Considerations

2-Methylnaphthalene is considered to be a hazardous substance. It is toxic if swallowed, inhaled, or absorbed through the skin. Prolonged or repeated exposure to the compound may cause irritation to the skin, eyes, and respiratory system. It is important to handle and store 2-Methylnaphthalene in a well-ventilated area and to use appropriate personal protective equipment.

See Also

• Naphthalene
• Polycyclic aromatic hydrocarbon
• Chemical synthesis
• Gas chromatography