Difference Between Benzyl Chloride and Benzoyl Chloride

The key difference benzyl chloride and benzoyl chloride is that benzyl chloride is an aromatic halide compound whereas benzoyl chloride is an acyl halide compound.

Benzyl halide and benzoyl halide are organochloride compounds. Both are colourless liquids having an irritating odour.

CONTENTS

1. Overview and Key Difference
2. What is Benzyl Chloride
3. What is Benzoyl Chloride
4. Similarities Between Benzyl Chloride and Benzoyl Chloride
5. Side by Side Comparison – Benzyl Chloride vs Benzoyl Chloride in Tabular Form
6. Summary

What is Benzyl Chloride?

Benzyl chloride is an organohalide compound having the chemical formula C6H5CH2Cl. It is a colourless liquid that is highly reactive; thus, it is used widely as a chemical building block. This liquid has a pungent odour.

Industrially, we can prepare benzyl chloride through the gas phase photochemical reaction between toluene and chlorine gas. This reaction gives benzyl chloride along with hydrochloric acid as the byproduct. Annually, manufacturers produce about 100,000 tons of benzyl chloride using this method. This reaction involves a free radical process, which includes intermediate free chlorine atoms. Moreover, there are some byproducts of this reaction, including benzal chloride and benzotrichloride. However, there are some other methods of producing benzyl chloride such as the Blanc chloromethylation of benzene.

The major application of benzyl chloride is using it as a precursor to benzyl esters that are useful as plasticizers, flavorants, and perfumes. Moreover, benzyl chloride is used to produce benzyl cyanide that is important as a precursor for the phenylacetic acid (a precursor to pharmaceuticals).

More importantly, benzyl chloride is an alkylating agent. It is highly reactive and reacts rapidly with water, producing benzyl alcohol and HCl acid through a hydrolysis reaction. When this chemical substance comes in contact with the mucous membrane of our body, it causes hydrolysis, producing HCl acid. Therefore, we can identify benzyl chloride as a lachrymator. Moreover, this substance is very irritating to our skin.

What is Benzoyl Chloride?

Benzoyl chloride is an organohalide compound having the chemical formula C7H5ClO. This is a colourless liquid that is fuming and has an irritating odour. Mainly, this compound is useful for the production of peroxides and also in the production of dyes, perfumes, pharmaceuticals, and resins.

We can produce benzoyl chloride from benzotrichloride using either water or benzoic acid. This compound is an acyl chloride compound. As with other acyl chlorides, we can generate this compound from the parent acid and chlorinating agents such as phosphorous pentachloride, thionyl chloride, etc. Chlorination of benzyl alcohol is another method, which was an early method of benzoyl chloride production.

Upon reaction with water, this compound can form HCl acid and benzoic acid. It can react with alcohols, giving esters. Further, this compound can react with amines, forming the corresponding amide. Apart from that, benzoyl chloride is a common reagent in polymer chemistry.

What are the Similarities Between Benzyl Chloride and Benzoyl Chloride?

• Benzyl Chloride and Benzoyl Chloride are colourless liquids.
• They are organohalide compounds.
• Both can form HCl acid upon reaction with water.

What is the Difference Between Benzyl Chloride and Benzoyl Chloride?

Benzyl halide and benzoyl halide are organochloride compounds. The key difference benzyl chloride and benzoyl chloride is that benzyl chloride is an aromatic halide compound whereas benzoyl chloride is an acyl halide compound. Moreover, benzyl halide is made from chloride through the gas phase photochemical reaction between toluene and chlorine gas while benzoyl halide is made from benzotrichloride using either water or benzoic acid.

Below infographic sums up the differences benzyl chloride and benzoyl chloride in tabular form for side by side comparison.

Summary – Benzyl Chloride vs Benzoyl Chloride

Benzyl chloride is an organohalide compound having the chemical formula C₆H₅CH₂Cl while Benzoyl chloride is an organohalide compound having the chemical formula C₇H₅ClO. The key difference benzyl chloride and benzoyl chloride is that benzyl chloride is an aromatic halide compound whereas benzoyl chloride is an acyl halide compound.

Reference:

1. “Benzoyl Chloride.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.

Image Courtesy:

1. “Benzyl chloride” By Edgar181 – Own work (Public Domain) via Commons Wikimedia

2. “Benzoyl Chloride” By Alberrosidus – Own work (CC BY-SA 3.0) via Commons Wikimedia