When the hydroxyls in the benzyl acid is replaced by chloride atoms, benzoyl chloride is synthesized. Benzoyl chloride is a kind of colorless liquid with pungent odor. It is also a kind of transparent and combustible liquid. When it is exposed in the air, it generates smoke. Its boiling point is 197.2℃and its relative density is 1.2120 (20/4℃). Its freezing point is -1.0℃and its melting point is-1.0℃. Its reflective index is 1.5537 and its flashing point is 88℃. Its vapor has lachrymation effect. It is soluble in ether, chloroform carbon disulfide and benzene. When it meets water or alcohols, it is gradually decomposed into benzyl acid and benzamine or ethyl benzoate and hydrogen chloride.

There are mainly two ways to produce benzoyl chloride. The first way to produce benzoyl chloride is to use toluene as raw material to react with chlorine under illumination and the side chain is chloridized into benzyl chloride which later is hydrolyzed into benzoyl chloride in acidic medium and releases hydrogen chloride gas. It is advisable to use water to absorb the gas in the production of benzoyl chloride. The second way to produce benzoyl chloride is to acquire it from the reaction of benzyl acid and phosgene. Put the benzyl acid into an actinic furnace and heat the furnace to 140-150℃. Then let in phosgene. The exhaust after the reaction contains chlorine hydrogen and residual phosgene, which can't be released until they are treated with alkali. In the end of the reaction, the temperature is -2-3℃. After the exhaust is cleared out, the pressure drops and the finish product is acquired after distillation. Industrial benzoyl chloride is a kind of light yellow and transparent liquid. Its pureness is above 98%. Modern industry usually acquires benzoyl chloride from the reaction of benzyl acid and benzylidene acetone. Benzaldehyde can be directly chloridized into chloride.

Benzoyl chloride is used as organic synthesis, dyes and pharmaceutical raw materials, and it is also used for manufacturing initiator benzoyl peroxide, peroxide benzyl acid tart-butyl Easter, and pesticide herbicide, etc. In manufacturing pesticides, it is the intermediate of a new type induction pesticide. Benzoyl chloride is an important chemical reagent of benzoylation and benzyl. Most benzoyl chloride is used to produce benzoyl peroxide. It is also used to produce important chemical raw materials, such as biphenyl ketone, benzyl benzoate, benzyl cellulose and benzamine and so on. Besides, when benzoyl chloride reacts with benzyl acid, they can produce benzyl acid anhydrides. Products of benzoyl chloride series are very widely applied in industry and in our daily life.

With the development of technology, products of benzoyl chloride series will be more and more commonly used and bring the society tremendous wealth.