4-Chlorobenzoyl chloride
[CAS# 122-01-0]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Carboxylic acid halide
• Name: 4-Chlorobenzoyl chloride
• Synonyms: PCOC; p-Chlorobenzoly chloride; 4-Chlorobenzoic acid chloride
• Molecular Formula: C₇H₄Cl₂O
• Molecular Weight: 175.01
• CAS Registry Number: 122-01-0
• EC Number: 204-515-3
• SMILES: C1=CC(=CC=C1C(=O)Cl)Cl

Properties

• Density: 1.377
• Melting point: 12-14 °C
• Boiling point: 222 °C
• Refractive index: 1.577-1.579
• Flash point: 105 °C

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H314-H318-H319-H335
• Safety Statements: P260-P261-P264-P264+P265-P271-P280-P301+P330+P331-P302+P361+P354-P304+P340-P305+P351+P338-P305+P354+P338-P316-P317-P319-P321-P337+P317-P363-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Skin irritation	Skin Irrit.	2	H315
Skin sensitization	Skin Sens.	1B	H317

Discovery and Applications

4-Chlorobenzoyl chloride is an aromatic acid chloride with a chlorine atom attached to the benzene ring at the para position. This compound is widely used in organic synthesis as a reactive intermediate due to the presence of the highly reactive acyl chloride group. The combination of the electron-withdrawing chlorine substituent and the acyl chloride moiety enhances its reactivity, making it useful in the production of pharmaceuticals, agrochemicals, and polymers.

The discovery of 4-chlorobenzoyl chloride can be traced back to advancements in the study of acid chlorides and their applications in chemical synthesis. Its ability to react readily with nucleophiles, such as amines and alcohols, has made it a valuable reagent in creating a variety of functionalized organic compounds. The chlorine atom further enhances the electrophilicity of the acyl chloride group, facilitating reactions with a wide range of substrates.

In pharmaceutical applications, 4-chlorobenzoyl chloride is frequently used as an intermediate in the synthesis of active pharmaceutical ingredients (APIs). It is involved in the production of drugs that require the introduction of acyl groups to enhance pharmacological properties. The compound's reactivity allows for the formation of amides and esters, which are key functional groups in many medicinal compounds. These transformations are often employed to increase the bioavailability and stability of therapeutic agents.

In the agrochemical industry, 4-chlorobenzoyl chloride plays a role in the synthesis of pesticides and herbicides. Its use as a building block for chlorinated aromatic compounds contributes to the development of chemicals that protect crops from pests while minimizing environmental impact. The versatility of 4-chlorobenzoyl chloride in forming derivatives that exhibit strong pesticidal properties ensures its continued importance in agricultural chemistry.

Additionally, 4-chlorobenzoyl chloride is employed in polymer chemistry, particularly in the production of specialty polymers and coatings. Its reactivity with alcohols and amines leads to the formation of polyesters and polyamides, which are valued for their mechanical strength, chemical resistance, and durability. These polymers find applications in high-performance materials used in automotive, aerospace, and industrial coatings.

The diverse applications of 4-chlorobenzoyl chloride in pharmaceuticals, agrochemicals, and polymers highlight its importance as a versatile intermediate in organic synthesis. Its reactivity and ability to form a wide range of derivatives make it a crucial compound in modern industrial chemistry.

References

2018. Chemical Transformations of Tetracyclo[3.3.1.13,7.01,3]decane (1,3-Dehydroadamantane): VI. Reactions of 1,3-Dehydroadamantane with Carboxylic Acid Chlorides. Russian Journal of Organic Chemistry.
DOI: 10.1134/s1070428018060039

2019. Green Synthetic Approach and Antimicrobial Evaluation for Some Novel Pyridyl Benzoate Derivatives. Russian Journal of Organic Chemistry.
DOI: 10.1134/s1070428019070200

2023. 1,3-Dehydroadamantane and Its Derivatives: A Versatile Synthetic Platform for the Preparation of Functional Compounds with a Cage Structure. A Review. Doklady Chemistry.
DOI: 10.1134/s0012500823600566