chlorobenzene

Chlorobenzene is an aromatic organic compound with the formula C6H5Cl. It consists of a benzene ring bearing a single chlorine substituent. It is a colorless to pale liquid that is flammable, with a boiling point around 132°C, a density near 1.11 g/cm3, and limited solubility in water. It is generally miscible with many organic solvents and is commonly used as a solvent in industrial chemistry.

Production and purification: Chlorobenzene is mainly produced by direct chlorination of benzene in the presence of catalysts such as ferric chloride or iron chloride. This process yields monochlorobenzene along with smaller amounts of other chlorinated benzenes; purification is accomplished by fractional distillation to isolate monochlorobenzene.

Uses and applications: It serves as a solvent for resins, fats, oils, dyes, and pharmaceuticals, and is a versatile chemical intermediate. It is a precursor for the production of phenol and various other chlorinated aromatics. In some older processes, chlorobenzene is converted to phenol by hydrolysis, illustrating its role as a feedstock for further chemical synthesis.

Reactivity: The chlorine substituent is strongly deactivating for electrophilic aromatic substitution, making chlorobenzene less reactive than benzene in such reactions. Under forcing conditions, it can undergo certain substitutions, such as nucleophilic displacement to form phenoxide or other derivatives.

Safety and environmental considerations: Chlorobenzene is toxic by inhalation and dermal exposure and can affect the central nervous system and liver. It is flammable and should be stored in a well-ventilated area away from ignition sources. It is persistent in the environment and requires careful handling, spill containment, and proper disposal.