Chlorobenzene: Preparation, Properties and uses

Preparation

Laboratory Method

Aniline: Benzenediazonium chloride is obtained by replicating aniline with a mixture of NaNO2 and HCl at 0–5°C. Chlorobenzene is obtained by heating benzenediazonium chloride in the presence of cupreous chloride and hydrochloric acid.

C6H5NH2 + NH2 + HCl → C6H5 — N = N — Cl + 2H2O

The first reaction is called diazotization reaction and the second reaction is called sandmeyer reaction.

Read more about diazotization reaction and sandmeyer reaction

C6H5 — N = N — Cl → C6H5Cl + N2

Industrial Method

Chlorobenzene is obtained by mixing a mixture of benzene vapors, hydrogen chloride gas and oxygen (oxygen) at 250°C on a copper oxide catalyst. This reaction is used for the industrial manufacture of chlorobenzene. This method of industrial manufacture of chlorobenzene is called Rasching method.

2C6H6 + 2HCl + O2 → 2C6H5Cl + 2H2O

Physical properties

chlorobenzene is a colorless, volatile and aromatic liquid. Its boiling point is 132°C. It is insoluble in water and soluble in alcohol and ether. It is heavier than water and its relative density is 1.12.

The reaction of Chlorine Atom

Reaction with NaOH: phenol is obtained by heating chlorobenzene with aqueous NaOH at about 300°C.

C6H5Cl + NaOH → C6H5OH + NaCl

Reaction with Ammonia: Aniline is obtained by heating chlorobenzene with ammonia at high pressure and around 250°C in the presence of Cu2O.

C6H5Cl + NH3 → C6H5NH2 + HCl

Aniline is also obtained when chlorobenzene is reacted with NaNH2 or KNH2 in a fluid ammonia solution.

C6H5Cl + NaNH2 → C6H5NH2 + NaCl

Reaction with cuprous cyanide: Phenyl cyanide (benzonitrile) is obtained by heating chlorobenzene with cuprous cyanide (CuCN) at about 250°C in the presence of pyridone.

C6H5Cl + CuCN → C6H5CN + CuCl

Reduction: On the reaction of chlorobenzene with Na — Hg and water, it is reduced and benzene is obtained. This reaction can also be carried out by Ni Al alloy and NaOH.

C6H5Cl + 2H → C6H6 + HCl

Halogenation: A mixture of ortho and para diChlorobenzene is obtained when chlorine is reacted with chlorine in the absence of sunlight and in the presence of halogen carrier.

Nitration: A mixture of ortho and para chloro nitrobenzene is obtained by the reaction of chlorobenzene with concentrated HNO3 and concentrated H2SO4.

Sulfuration: A mixture of ortho and para Chlorobenzene sulfonic acid is obtained by the reaction of Chlorobenzene with the corresponding H2SO4.

Reaction with chloral: pp-Dichloro-diphenyl-trichloroethane formed upon heating Chlorobenzene with chloral in the presence of concentrated sulfuric acid. It is also called D.D.T..

It is a strong and major disinfectant. for more detail click here

What is chlorobenzene used for?

It is used in the manufacture of aniline, phenole, chloronitrobenzene, and disinfectant DDT.