4-Chlorobenzaldehyde
[CAS# 104-88-1]

Identification

• Classification: Organic raw materials >> Aldehyde
• Name: 4-Chlorobenzaldehyde
• Synonyms: p-Chlorobenzenecarboxaldehyde; 4-Chlorobenzoic aldehyde; PCAD
• Molecular Formula: C₇H₅ClO
• Molecular Weight: 140.57
• CAS Registry Number: 104-88-1
• EC Number: 203-247-4
• SMILES: C1=CC(=CC=C1C=O)Cl

Properties

• Density: 1.196
• Melting point: 46 °C
• Boiling point: 214 °C
• Flash point: 88 °C
• Water solubility: 935 mg/L (20 °C)

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H302-H315-H317-H319-H335-H411
• Safety Statements: P261-P264-P264+P265-P270-P271-P272-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Specific target organ toxicity - single exposure	STOT SE	2	H371
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413

Discovery and Applications

4-Chlorobenzaldehyde is an aromatic aldehyde with a chlorine atom attached to the benzene ring in the para position relative to the aldehyde group. This compound is widely used as an intermediate in the synthesis of various chemicals, including pharmaceuticals, agrochemicals, and dyes. The reactivity of both the aldehyde group and the chlorine atom makes 4-chlorobenzaldehyde a valuable building block in organic synthesis.

The discovery of 4-chlorobenzaldehyde dates back to early developments in organic chemistry, particularly in the exploration of substituted benzaldehydes and their derivatives. Its relatively simple structure, combined with its versatility, has made it an important compound in industrial chemistry. The chlorine substituent imparts unique electronic properties to the molecule, affecting its reactivity and making it useful in the synthesis of more complex chemical structures.

In the pharmaceutical industry, 4-chlorobenzaldehyde is used as a precursor in the production of active pharmaceutical ingredients (APIs). It is often employed in the synthesis of intermediates for drugs that target a variety of conditions, including inflammation and infections. The aldehyde group allows for easy modifications and transformations into different functional groups, providing flexibility in drug design.

4-Chlorobenzaldehyde also plays a significant role in the agrochemical sector, where it serves as a starting material for the production of herbicides, fungicides, and insecticides. Its ability to form stable derivatives contributes to the development of compounds that protect crops from pests and diseases while minimizing environmental impact.

In the dye industry, 4-chlorobenzaldehyde is a key intermediate in the production of colorants used in textiles and plastics. Its reactivity allows for the creation of dyes that exhibit good lightfastness and durability. Additionally, the compound’s chlorine substituent enhances the dye’s binding to fabrics, ensuring that the color remains vibrant and resistant to fading.

Overall, 4-chlorobenzaldehyde’s broad range of applications across multiple industries highlights its importance as a versatile chemical intermediate. Its role in pharmaceuticals, agrochemicals, and dyes ensures that it remains a key compound in modern industrial chemistry.

References

2013. Asymmetric Aldol Reactions between Acetone and Benzaldehydes Catalyzed by Chiral Zn2+ Complexes of Aminoacyl 1,4,7,10‐Tetraazacyclododecane: Fine‐Tuning of the Amino‐Acid Side Chains and a Revised Reaction Mechanism. Chemistry - An Asian Journal, 8(6), 23780779.
DOI: 10.1002/asia.201300308

2024. Green heterogeneous nickel-chromium oxide catalyst for solvent-free, room-temperature Knoevenagel condensation reaction. Journal of Chemical Sciences, 136, 2292.
DOI: 10.1007/s12039-024-02292-4

2024. Introduction of a new cobalt-containing Lewis acidic ionic liquid catalyst for the reduction of nitroaromatic compounds and aldehydes and one-pot reductive acetylation of arylaldehydes. Research on Chemical Intermediates, 50, 5430.
DOI: 10.1007/s11164-024-05430-2