Chlorobenzene is an aromatic organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 with the chemical formula C₆H₅Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.
Chlorobenzene once was used in the manufacture of certain pesticide

Pesticide

Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...

s, most notably DDT

DDT

DDT is one of the most well-known synthetic insecticides. It is a chemical with a long, unique, and controversial history....

 by reaction with chloral

Chloral

Chloral, also known as trichloroacetaldehyde, is the organic compound with the formula Cl3CCHO. This aldehyde is a colourless oily liquid that is soluble in a wide range of solvents...

 (trichloroacetaldehyde), but this application has declined with the diminished use of DDT.